A One Off Bonus Post

I regard the search for historical examples of "one off" as ongoing and always like to refresh it when I have the opportunity.

Recently I've been conducting searches on archive.org. It's not an easy database to search because so many journals are dated by the date of their first issue, rather than their actual publication date, rather like the 1975 issue of the British Bee Journal is dated 1882 on Google Books. This makes it seem like a lot of results are older than they really are, requiring manual checks to make sure. However, it contains a few journals which I'd only ever seen in hard copy and had to search manually but which I've now been able to search electronically, as well as others I'd never checked before. I've also searched a number of other databases, such as the collection on hathitrust.org.

I've made a few interesting discoveries.

ONE OFF INSTANCE

I'd always assumed that there must exist earlier examples of "one off instance" than the earliest found so far, which are all from the 1980s. After all, we have examples in print of "one off experience", "one off situation", "one off occasion", "one off incident" and "one off occurrence" from the 1970s, so surely we should also have at least one example of "one off instance" in that decade.

Well I finally found one. It's from a 1976 book entitled Understanding Organisations by Charles B. Handy. The database at archive.org doesn't actually have the edition published in 1976 but it does have a 1981 reprint of this book containing this phrase. From this lead I then checked the 1976 edition and can confirm it's in there. The extract is as below:

"Managerial judgement is involved in deciding whether the problem is a one-off instance or a symptom of a deeper malaise".

ONE FROM 1893

Can we find any more examples of "one off" being used in the nineteenth century?

Yes, I managed to dig out a rather interesting letter to the editor of The Foundry of 10 May 1893 which was then a relatively new trade journal published in Detroit, Michigan, having started life in 1892. The letter, dated 24 March 1893, is from R.A. Hadfield of the Hadfield Steel Foundry Company of Sheffield (England) as follows:

We can see that Hadfield, after asking for a complete set of back issues, makes a little manufacturing joke by saying:

"I hope you will be able to "cast" me the January number, but do not make the usual charge for "one off"."

This is interesting in two respects.

Firstly, it shows that "one off" was being identified as something separate from other numbers off, such as two off, three off etc. as early as 1893 (and what Hadfield wrote in that letter might well have been something that could have been written in 1888). But I'm not seeing anything here that demonstrates that "one off" meant something unique. If anything, Hadfield seems to have been equating "one off" with expensive. But essentially it's still just a quantity of one.

Secondly, and I think of crucial importance, Hadfield did not say that he hoped that the journal would make the usual high charge for "a one off". Remember, this is five years after James Maybrick is supposed to have written about "a one off instance". No, what we see here is that Hadfield flags his joke by saying that he hopes that the journal will be able to "cast" him the January issue before introducing "one off", meaning one casting off, with both of those words (or phrase in the case of "one off") wrapped in quotation marks to indicate not only that they go together but that they are not being used in a normal way (i.e. one does not "cast" a journal).

As I wrote in my blog post Let's Trip Over It Again published on 7 May 2024, prior to undertaking my searches on archive.org, a patternmaker in the 19th century would not have written of "a one off casting...the way that would have been put by pattern makers in the 19th century, if they ever said or wrote these words, was "casting one off"." This is entirely corroborated by Hadfield's letter in which he is playing on the words: "cast...one off". It tells us nothing new about the use of language.

While Hadfield's letter is certainly an interesting factor in the evolution of "one off" it was still only a quantity at this time, not an expression of it's own to mean something unique or unrepeated. The letter confirms to my mind that no one would or could have written an expression such as "a one off instance" in 1893, let alone in 1888. At this time, we clearly don't even have anyone speaking of "a one off job".

THE FOUNDRY TRADE JOURNAL

The Foundry Trade Journal and Pattern Maker to give it its full name (but I shall refer to it as The Foundry Trade Journal) was a British publication which commenced in 1902. In its issue of 18 February 1904 we find some important early mentions of "one off" in an article entitled 'A Few Remarks on Jobbing Shop Management' by "An Old Moulder". I already cited this in full in my One Off Article (which is now updated) but it's worth reminding ourselves of it to set the rest of this article in context:

"Some of these jobs the writer has found that, to make them simple, the amount of tackle to be made would cost considerably more than, perhaps, the value of the casting. Therefore, there only being one off, you endeavour to do without the tackle, and make the job in its complicated way. Bearing in mind that there is only one off, and if I can only bring it through..."

The article continues...

"Again, I may venture to suggest that there are so many patterns which come into a Jobbing Foundry for one off and two off that, if they were given in hand just as they come, the amount of boxes required would be considerable; and also to make them singly would result in costing a great amount. for labour."

What I would venture to suggest is that where we find "one off" and "two off" in the same sentence it is clear that we are dealing with mentions of quantities, not indications of uniqueness.

The absence of any mention of a "one off job" should also be noted

THE FOUNDRY: UP TO 1912

Searchable issues of The Foundry going back to 1892 are available on archive.org. A search of this publication from 1892 onwards produces, with one uncertain exception, no further mention of "one off" until September 1912 when the journal carried a report of T.R. Schofield's paper presented at the Cardiff convention of the British Foundrymen's Association when he famously referred to a "one off job".

The exception is in The Foundry of September 1904 where the words "one" and "off" are certainly found next to each other in an article entitled "The Foundry Apprentice as seen in one Shop" by Charles H. Thomas and N.J Newark:

It's likely that this is no different in usage to talking about a pack of cards and taking one off the top of the deck. It could, possibly, be that the advice being given to the boy here is actually in the form of: "If there are more than "one off" the pattern...try a different way", although the word "is" in that sentence would suit better than "are". But I don't think this is what is being said. I rather think that the word "off" is being used in the manufacturing sense of casting off from a pattern but the word "one" is being in its normal sense as a number, with no intention of forming an expression of "one off" (so that it should be read "If there are more than one "off the pattern"...try a different way") so we can probably ignore that one and conclude that, with the exception of Hadfield's letter, there are no examples of "one off" in The Foundry between 1892 and 1912.

During that period of 20 years we do find mentions of jobs involving "one casting" from a pattern such as the below from The Foundry of March 1894 in an article 'Lessons in Patternmaking for Manual Training Schools' by P.S. Dingey:

:

"If we want to make it quickly to get but one casting from it..."

We also have this from an editorial piece in The Foundry of October 1896 which speaks of a person who "only wanted one casting of each pattern":

"He can do so because he goes at his work as if he was running a jobbing shop and only wanted one casting of each pattern."

Then we have examples of jobs where "only one casting is required" in an article by John M. Richardson entitled 'What is a Good Pattern' in The Foundry of February 1899 as below:

"And, working on this principle, it is a good deal like filching money out of someone's pocket to fuss and putter and be over-exact and nice on some cheap job where only one casting is required...Where only one casting is wanted it is usually made of one piece as nearly as possible..."

Then in the February 1905 issue of The Foundry, we have a mention in an article entitled

'A Job Shop Pinion Job' by 'Wilber' that someone "could do the cheap, one casting job in a way that was a delight" [NB this article had appeared in the September 1904 issue of The Patternmaker].

A couple of months later, in the April 1905 edition, in a piece entitled 'Trouble with the Foundryman' it was stated that "there was only one casting wanted from the pattern".

These were opportunities for the expression "one off" to be used, especially instead of "one casting job", and, while their absence doesn't prove that the expression "one off job" didn't exist at the time (as I have found the use of "one casting job" as late as 1943), the complete absence of its use anywhere prior to 1912 strongly suggests that it did not.

AFTER 1912

After 1912 the floodgates opened to some extent in respect of the expression "one off job" especially in the UK.

From The Foundry Trade Journal of October 1913:

"For a "one-off" job, fillets in the pattern may be dispensed with".

And from The Foundry Trade Journal of December 1913 in respect of an article by D. Gordon entitled 'Reducing pattern costs':

"the latter process described by Mr Gordon was more suitable for "one off" jobs."

Note that this is from a record of an oral discussion at a meeting.

Then we have this from the April 1914 issue of The Foundry Trade Journal:

This form of instruction: "As little time on the pattern as possible [means that a patternmaker should use] only one off" harks back to the earlier use of "one off" where it is more of a quantity.

The same is true of this mention of "the "one off" variety" from August 1914, in an article by D. Gordon, which is reminiscent of Garscadden's "one off way":

"It is very liable to twist, split and warp, and is thus only employed within the narrow limits of the "one off" variety".

We find "one off variety" in issues of May 1915 (also in an article by D. Gordon) and again, more interestingly, in another article by D. Gordon from August 1915 as below:

"In many instances jobs of the “ rush,’’ experimental, or ‘‘ one off ’’ variety, tax to the utmost the capacity and ingenuity of both pattern-shops and foundry for the production of the required castings....in general engineering patternmaking, ignored and not appreciated or applied to those classes of work for which it is eminently suit able, i.e., the ‘“‘ rush,’’ experimental, or "one off” variety."

I say this is interesting because, as mentioned in my One Off Article, "one off" seems to be synonymous in Mr Gordon's mind with the words "rush" and "experimental" as opposed to "unique" and "unrepeated". We shouldn't necessarily assume that "one off" meant the same thing in 1915 as it meant in, say, 1935, or as it means today.

In The Foundry Trade Journal of October 1915 we find another old-fashioned sentence in an article by someone calling himself "Jay Bee":

"A certain amount of discrimination is necessary in these matters, because some jobs which seem at first glance good subjects for jolting do not on close examination recommend themselves so much when one considers the plant he may have to provide, and perhaps a patternmaker’s time to make alterations to a pattern which may have only one off."

In the issue of April 1916 a J.R. Moorhouse, in an article entitled "Unorthodox Patterns", said:

"It is admitted there should be no excuse for an unworkable pattern, but there are occasions when conditions positively compel the patternmaker to pass on to the foundry patterns that are scarcely worth the name. These add considerably to the foundry costs, and result in unsatisfactory castings —a very questionable economy. But apart from these, a pattern may be quite practicable and leave much for the moulder to do to complete his mould. Of such nature are the "one-off " variety of patterns; and just where the line should be drawn in regard to what should be done in the pattern-shop and what left for the foundry to do, in view of the entire cost, is of itself a controversial subject."

The expression "one off variety of patterns" could have been expressed more concisely as "one off patterns" but Moorhouse, like Jay Bee, is also using somewhat outdated language.

In The Foundry Trade Journal of September 1918, we have another example of the expression "one off job" in an article by James Edgar who, with Ben Shaw, would go on to become one of the most enthusiastic adopters of that expression:

"They are usually one-off jobs..."

James Edgar again uses the expression in an article entitled 'Timber for Patternmaking' in The Foundry Trade Journal of September 1919:

"In most shots there are two or three different grades of patterns, those from which hundreds of castings will be made, others which will be used occasionally, and the cheapest class, which are for one-off jobs."

In The Foundry Trade Journal of February 1920, we find a transcript of some comments by a Mr Shaw, probably not Ben Shaw, at a meeting of the Sheffield and District Branch of the Institute of British Foundrymen held in Sheffield on 3 December 1919:

"But there was often a bonus and an understanding made with the men for extra work, because often a job was "one off" and a piece-rate could not be fixed."

It may be significant that Shaw didn't say that the job was a one off.

James Edgar mentioned one off jobs in an article entitled 'Dowels' in the Foundry Trade Journal of March 1920:

"This can be understood in the case of "one-off" jobs, or in special work, but not otherwise."

In the May 1920 issue of The Foundry Trade Journal, Alexander Hayes referred to London being notorious for having foundries with "trifling one-off jobs":

In June 1920, Ben Shaw and James Edgar spoke of special tackle "for what may be only one-off jobs":

James Edgar once again mentions "a one-off job" in the issue of The Foundry Trade Journal dated 27 January 1921 as he speaks of "putting a very fine finish on a one-off job".:

This is 14 February 1922 by someone writing under the name of "Ecossais" who refers to the making of certain pipes as being "generally one-off jobs".

Going back to the American Journal, The Foundry, after 1912, there were no more uses of "one off" until 1919 when we find "slide and cast one off it solid, core prints and all" which is another ambiguous usage but then in its issue of 1 March 1922 we have a definite usage as Ben Shaw and James Edgar wrote: "If such a casting was wanted in a hurry - a one off job - there would be no question of molding it on a machine":

It's rather interesting because if a one off job involves wanting a casting in a hurry, it rather suggests that "one off" in 1922 carried the meaning of "hurry-up" or "rush" rather than "unique" but it's by no means clear.

From 1922 onwards we have quite a considerable number of mentions of "one off job(s)" in the Foundry Trade Journal as follows:

9 March 1922, Shaw & Edgar:

"If such a casting was wanted quickly - a one off job - there would be no question of moulding it on a machine".

The defining characteristic of a one off job, again, seems to be one wanted quickly.

1 June 1922 by W. Pyatt:

"One baseplate which came to the writer's notice some time ago was a "one off" job, "very urgent" and low priced".

2 November 1922, Ben Shaw and James Edgar:

"For a one off job it may be quite satisfactory to leave the stopping over to the moulder, but for repetition work a core-box should be made."

11 January 1923, Ben Shaw and James Edgar:

"There should be as few loose pieces as possible, and when some are necessary, except for one-off jobs, they should be dovetailed or dowelled in position in order that they may be accurately replaced."

25 January 1923, Shaw & Edgar:

"For one-off jobs core-frames are in many cases satisfactory, and, in some instances, when a number of cores are required, a core-frame or plate may be a more practical as well as a more economical way of obtaining a core than with a core-box."

1 March 1923, Shaw & Edgar:

"When a loam core-box is prepared in this way, and a few cores are to be made from it, the first core should not be built until the box has been dried, but for ordinary one-off jobs, if the loam is allowed to stiffen, the core can be made in it quite satisfactorily without it being thoroughly dried."

8 March 1923, Shaw & Edgar:

"It is generally assumed that this type of pattern is only suitable for a one-off job, as in the case of a vertically swept pattern, but this assumption is erroneous because such a pattern may be used many times with reasonable care particularly if it is coated with tar and thoroughly dried."

22 March 1923, Shaw & Edgar:

"While it is an excusable practice to make a very cheap pattern for a one-off job, yet if the cost is run up in the foundry it is inexcusable."

5 April 1923 (not Shaw & Edgar this time but a Mr Hardyman):

"The only skilled moulders were those kept for jigs and one-off jobs, which it would be ridiculous to put on a machine."

26 July 1923, Shaw & Edgar:

"The several thicknesses would be glued back to back, and it would not be necessary to either paint or varnish the pattern, because it would be a one-off job."

This continued into 1924 (with no contributions from Shaw & Edgar in this year) firstly from its issue of 10 July 1924:

"A few roughly shaped pieces of wood held together by nails are all that is required for a one off job."

From the issue of 23 October 1924:

"For one-off jobs the casting is invariably preferred because it is cheaper...The castings discussed above have been one-off jobs..."

From the issue of 18 December 1924:

"It is not suggested that, in all cases where a casting similar to Fig. 1 is required, the method described in this article should be adopted, but it served well for a one-off job that was required at shortest notice....Being a one-off job it was made of yellow pine".

And from the issue of 30 December 1924:

"This may not matter so much in the case of a one-off job but, if many castings are required, it is important."

In 1925, this continued, as we find three mentions of "one off jobs" in the Foundry Trade Journal.

The first, in its issue of 23 July 1925:

"...the sizes and shape of branches vary, generally come under the category of one-off jobs..."

The second, in its issue of 30 July 1925:

"This method does not take much extra time or material, and it should always be adopted with lagged work for such patterns, unless for one-off jobs."

Then in its issue of 27 August 1925:

"Foundries specialising in engineers' castings constantly encounter a number of one-off jobs....A four-groove pulley would not normally be considered a "one-off" job, but the one thing being described, and as shown in Fig. 1, is definitely "bastard".

The reason I reproduce all these examples from the 1920s is to show the explosion of use of "one off job" in this decade compared to the absence of any uses at all in the years before 1912.

Returning to the Foundry, from which, as I've mentioned, issues go back to 1892, we find further mentions of "one off jobs" during the 1920s and 1930s hence:

In1925 there is a reference to a new engineering practice which is "eliminating the one-off job"  in the issue of The Foundry of December 1925:

"Changes have been forced on the foundryman and adopted not because he believes that better castings can be produced by one method as compared with others, but owing to the general evolution of engineering practice which is slowly and surely eliminating the one-off job."

Then we find the following references:

"Certainly patternmaking methods automatically are ruled out where speed of production is the paramount feature. The same holds true on many large one-off jobs" .(15 March 1926).

"Some of the jobs were and are of a repetition character, but the great majority were and are in the one-off class where patterns, flasks and methods had to be adapted in a special manner to meet individual requirements." (15 October 1930).

"On a pattern to be used frequently, the flange would have been fitted with a turned male and female guide, but for a one-off casting the nails served adequately" (March 1935).

"In many instances the method is mandatory since these one-off patterns are of the cheapest and elementary construction which would involve an excessive amount of hand finishing if the mold was made in the usual manner" (December 1936).

"Of course, at the time this was an emergency one-off job. Later a special pattern was made." (April 1940).

"Spraying the cores with molasses water and then with oil produces a beautiful hard, smooth core, but is no more necessary than a piano finish on a one-off pattern" (September 1943).

"Orders for one-off, intermittent or protracted runs provide a problem made worse by customers’ neglect in requesting the patterns' immediate return after completion of the casting order ." (September 1946).

"Possibly four risers would serve, but since apparently it is a one-off job, prudence suggests the use of six spaced equidistantly". (December 1946).

"For a one-off job this pattern would be set in false cope and rolled over" (May 1948).

We also find an interesting reference in The Foundry of 1 February 1946:

I say it's interesting because talking about marking a blueprint "Cast Iron - One Off - Rush" is going back to the 19th century way that "one off" was used as a pure notation of quantity as the manufacturer is here simply being told to make one of these items as a rush job for the navy.

AMERICAN MACHINIST

A third journal I was able to word search was American Machinist, issues of which go back all the way to 1877. In this series we find two uses of use of "one off" from the nineteenth century.

The first is from an issue dated 5 June 1890 and it's exactly what we would expect:

Some notations on a mechanical drawing saying "1 off". No "meaning" at all, no expression or phrase.

Then in American Machinist of 14 April 1898 we have another nineteenth century mention in a letter to the editor by "Molder" entitled 'A Molder on Pattern Makers' as follows:

In saying "only one off", he's talking about casting one off, which is exactly what we would expect for this time period.

In the 6 January 1910 issue of American Machinist, it is said that all one has to do is order "one off in T.C.K" and within 24 you apparently have a new milling cutter in your hands.

T.C.K. was a form of steel sold by a French firm, Messrs Horstman.

Again, for this time period, an expression such as "order one off", similar to cast one off, is just what we would expect.

In American Machinist of 7 August 1913, we find some comments by D. Gordon (who was an English foundryman) in an article entitled 'Economic and Convenient Casting Practice' which is similar to what he would write a couple of years later in The Foundry Trade Journal:

So for Gordon in 1913 it would seem that "one off" class of work was the same as "experimental" or "breakdown" work. One can't help feeling that "one off" could, in theory, have come to mean experimental. But of course it never did (although we will see below that some people might have thought it did).

He was at it again in the 11 June 1914 issue:

"Hidden under the word convenience - a word covering a multitude of sins - patterns of the hurry-up, one off or experimental order, often prove to be exceedingly costly, both as regards their resultant castings and in the ultimate value of the finished work produced by their means."

Now, one off patterns are either experimental or "hurry--up" patterns. The fact that they often prove to be "exceedingly costly" seems to echo the point Mr Hadfield had made in his letter to The Foundry in 1893.

An article entitled 'How Would You Make This Casting' by John Compo in the 20 February 1919 issue of American Machinist contains the first mention in the journal of a one off job. It's rather interesting that Compo was responding to an article by M.E. Duggan from the American Machinist of 19 September 1918 in which Duggan had written:

'When but one or two castings are required the making of core boxes is but a waste of time, and this is often the reason why patterns for a one-casting job are so costly".

To this, Compo replied in February 1919:

"I take it that Mr. Duggan refers to a “one off,” or repair, job, which is a different matter entirely, and had I known, I could have given him a dozen rough but speedy ways of getting one casting."

Apart from the interesting way that Compo appears to change the wording of "one-casting job" to "one off...job", we can see that, in addition to experimental, breakdown, rush, hurry-up, we now have a one off job said to be the same as a repair job. It just seems to confirm that "one off" meant different things to different people and didn't automatically mean unique, unrepeated.

The same article, incidentally, went on to say that, "this is a hurry-up job also, and only one casting is required".

The next mention of a one off job in American Machinist was by another Englishman, James McLachlen, in an article entitled 'Sweeping Small Cores' in the December 1923 issue:

"...the always undesirable necessity for making a corebox for a "one off" job is thereby avoided, thus saving considerable time and expense."

In the same issue, an article by F.C. Edwards, also from England, entitled 'Two Ways of Making a Core - Discussion', stated:

'The requirements of both foundry and machine shop are thus fulfilled, and, with the pattern made cheaply enough for a "one off" job..."

There aren't any more mentions of one off jobs in this journal until 18 December 1930 when another Englishman mentioned them in a letter to the editor:

"Pattern dimensions on shop drawings are often unavoidable, especially on jig drawings, as these are usually "one off" jobs and it would not pay to make separate drawings for each department".

We have to wait until 1953 for the next appearance of the expression in the American Machinist and this one again is from an English writer, Clifford T. Bower of London:

"When a price has been quoted for a one-off job and the contract obtained, it is obviously more profitable to the contractor to reduce the production time to its lowest possible figure, since every hour that he saves from the estimated time is clear profit."

BREAK-DOWN JOBS

Going back to the nineteenth century, in American Machinist of 8 April 1882, Thomas Dyson West wrote:

"One is for melting special grades of iron, and the other to retain the bed in a cupola after melting a heat for a break-down job, or for a piece of casting that is wanted in a hurry".

A 'break-down job', by which someone needs a single urgent replacement machine part for a part which has broken, is an obvious description of what was also known in the nineteenth century as a repair job, rush job or "hurry-up" job and which would much later be known as a one off job.

We find the same expression in a letter to the editor published in American Machinist of 17 March 1888 from an F.B. Shaffer of Lancaster, Pennsylvania, who wrote:

'"n nearly every shop there is often occasion to run off a heat in a hurry for a break-down job and the expense of getting the cupola ready and the fuel consumed is more than the profits on the job...."

The letter continued:

"They are especially desirable when a customer comes in with a break down job, and must have it right off, as in a foundry nearly everything is wanted "to-day"."

That a break-down job could also be synonymous with a "one casting job" and thus a "one off job" is seen most clearly in this extract from a letter by a Louis Baden to the editor of American Machinist published in its issue of 4 May 1899:

As we can see, Mr Baden was here referring to "a one-casting break-down job".

For the record, in addition to the above, we find "break-down job" mentioned in issues of American Machinist of 6 June 1885, 12 February 1887, 15 March 1888, 7 March 1889, 1 November 1894 and also in the issue of The Foundry of 1 February 1896. Yet not a single mention of 'a one off job'.

Other expressions which could and have been used to describe a one off job are: temporary, emergency or occasional jobs. American Machinist of 19 April 1884 refers to an occasional job:

Here is a classic use of the expression "emergency job" which is expressly defined as a job not to be repeated (i.e. a one off job) found in American Machinist of 14 September 1899:

"...a good example of a shop sketch embracing all essential particulars for a quick emergency job not to be repeated".

In American Machinist of 6 April 1899 we also find mention of "drawings of special machines which are not to be repeated'" which can only be a convoluted way of saying either "one off jobs" or "one off machines":

SPECIAL JOBS

This is another classic from a letter written to American Machinist of 9 February 1899 by one G. H. Willard of Worcester, Massachusetts:

As can be seen, under the editorial heading of 'A Quickly Made Pattern', thus indicating a rush or hurry-up job, the writer states:

"Two patterns were made for a special job, and only one casting of each was wanted in brass".

It's hard to believe that the writer wouldn't have referred here to a one off job had the expression existed. There are numerous examples of mentions of "special jobs" in American Machinist during the 1870s and 1880s (e.g. issues of July 1878, 2 August 1879, 17 December 1881, 25 November 1882, 17 March 1883, 21 July 1883, 22 March 1883,17 October 1885, 26 December 1885, 9 January 1886, 8 October 1887, 19 November 1887, 21 April 1888, 2 June 1888, 10 November 1888). None for "one off jobs" though.

Just a couple of examples:

Firstly from the July 1878 issue:

"The most important is the system of making the principal parts of machines by duplication, so the work of assembling may be rapid and without additional labor in making perfect fits, and that when a part gets broken and worn out it can be replaced promptly without the trouble of a special job."

From the 17 October 1885 issue, in a piece entitled 'Book-keeping in Small Shops':

"Such a shop may do a special job, for example, and if no properly-itemized account is kept, a few months later such a job, if undertaking, is substantially a new one on which no data as to cost are at hand."

For the best possible example showing that a "special" job is the same as what might later be called a "one off" job we can turn to an article written by J.G. Stewart of North Ormsby, England, for an American journal, Transactions of the American Foundrymen's Society, dated June 1902 and entitled 'Foundry Accounting':

"Is it honest I would ask you? when a special job comes in (one or two castings off) and special tackle has to be made".

So we can see that Stewart has here helpfully defined a "special job" for us as (almost) a one off job but, of course, that expression didn't exist in 1902 so he's explained it as "one or two castings off".

CANADIAN MACHINERY

A fourth journal which contains a few relevant results is Canadian Machinery which was first published in 1905. It reported T.R. Schofield's famous paper/speech from 1912 in which he spoke of "the familiar "1 off" job" where the word "one was represented by the number 1.

I'm not entirely sure of the meaning of the below from Canadian Machinery of 17 April 1913:

"A wood plug was driven in the centre holes and the "patterns" were sent to the foundry to have "one off."

This, however, from the issue of Canadian Machinery dated 17 August 1916 is much clearer:

"The patternmaker should make a sketch of each job he finishes, stating whether it is a one-off pattern, a good skeleton, or a solid pattern, and underneath should be noted the cubic measurement of the timber used and the number of hours he has been on the job."

THE PATTERNMAKER

A fifth searchable journal I found was an American journal published in Cleveland, Ohio, called The Patternmaker. It commenced publication in March 1904 and in its first two years carried a considerable number of articles in which patternmakers discussed the best and cheapest way of designing a pattern for which only one casting was required, something we might today refer to as a one-off job (and was often referred to as such after 1912), but the authors of the articles in The Patternmaker of this time never did. From October 1905, The Patternmaker was subsumed into another publication called Wood Craft and the focus on patternmaking articles was greatly reduced as a result.

But for those first couple of years there were multiple examples of opportunities for the authors to refer to "one off jobs" if that expression had existed at the time but they never once did. To demonstrate this, I am going to reproduce all the occasions I found when they could have done so.

The first is from the April 1904 issue in an article entitled 'The Pattern Shop' by J.C. Warne:

"The grades of lumber to be used should vary as the job. I mean by this that for patterns from which only one casting is to be made, with little probability of another being made in the future, cheaper material can be utilized so long as the lumber is sound and free from checks."

And:

"It frequently happens that a pattern is required for only one casting."

The next example is from an article by H.L. Post entitled 'The Pattern Shop and the Foundry' in the May 1904 issue:

"We are all aware that at times when there is only one casting to be made from a pattern that it pays to make a cheap pattern and let the molder do a good part of the work in the foundry, which of course adds to the cost of the casting but reduces the cost of the pattern to such a degree that the time saved on the pattern would pay for twice the time spent by the molder."

This is from 'Pattern Loan Records' by R. W. MacDowell also in the May 1904 issue:

"Make sketches showing all the appliances which the patternmaker should furnish the molder when castings, shown finished by the accompanying drawings are wanted as follows: (1) for one casting. (b) for ten castings. (c) for one thousand castings."

From the same issue in an article by M. J. Golden entitled 'Patternmaking in the Technical School':

"First the student must determine in what respect he would have the pattern from which only one casting is to be made differ from the pattern from which a small number are to be gotten, and again how the pattern is modified for manufacturing purposes when a large number of castings are wanted."

The next is from the June 1904 issue written by J.L. Gard in an article entitled 'Job Shop Management':

"A pattern like this for one casting is a poor job, because the customer either pays for what he does not need, or the boss does not get paid for all the work he does."

From the July 1904 issue in 'Patternmaking in its Relation to Foundry Costs' by W.H. Parry:

"The making of patterns without fillets and marking the corners with dotted lines so that the molder is compelled to cut them cannot be excused upon the ground that there is one but casting wanted, as wood or leather fillets can be bought and applied cheaper than the cost of the modler's time in slicking the round corner'.

'Mechanics are Born Not Made' by Ben Wood in the August 1904 issue:

"I am surprised at some things I have seen in The Patternmaker. Such, for instance, as advising men to put up a pattern for one casting only, just so that it would come out of the sand, leaving the molder to do the rest.'

Also August 1904, 'Durability of Patterns' by Henry H. Parry:

"In instances where only one or a few castings are required there is no necessity for a pattern to be extra strong so long as it holds together to make these few impressions, and the workmanship may, in a measure at least, be slighted."

Also, from August 1904, by Vincent Colajezzi in an article entitled 'Amusement at the Firm's expense', we find mention of "break-down jobs" required in a rush which sound remarkably similar to what would later be called "one off jobs" which are also often wanted in a rush to replace a broken machine part:

"The break-down jobs occurred very often and were, of course, required in a rush."

'A Job Shop Pinion Job' by Wilber, September 1904:

"Jack...could do as good work as the best, and he could do the cheap, one casting job in a way that was a delight."

October 1904 issue editorial under the heading "Pattern Shop Conditions":

"It may be a little instructive to analyze these conditions a little. We know just as many patterns are required where one casting is to be made as where twenty castings of the same piece are wanted."

May 1905 issue:

"There was a great rush for the casting and the trouble made a great delay as there was only one casting wanted from the pattern."

From the June 1905 issue in reply to the above, this was written by 'A subscriber':

"...I do not approve of making it that way; neither do I think it necessary to make a core-box for the inside of a one-casting job."

Also from June 1905 in a piece called 'Shavings' written by 'A wandering patternmaker':

"As only one casting was required..".

July 1905 - anonymously written piece 'Gluing and Turning Segmental Patterns':

"If the pattern is used but once, and the casting is to be finished all over, then any shrinkage or warpage of the pattern will in all probability not affect the finished casting...If but one casting is to be made...".

Finally, in the May 1907 issue of what was now called 'Wood Craft' is an article entitled 'Time and Wood in Patternmaking' by 'Incognito':

"Of course the core-box pattern was not made of mahogany, as only one casting from it was necessary."

What we can see from the above is that despite so many opportunities to mention 'one off' or 'one off jobs', had that expression existed at the time, it never was mentioned. While this was an American journal (and Americans seem to have been less attached to the concept of "one off") it supports the contention that a "one off job" wasn't an expression known to patternmakers during the first decade of the twentieth century.

CASTINGS

A journal published in Cleveland, Ohio, called Castings, is also searchable from 1907 to 1912 (and the 1912 issue contains T.R. Schofield's paper mentioning a one off job.) In that journal we find:

'Practical Economy in Patternmaking and Molding' by Jabez Nell, February 1908:

'only one casting being needed...'.

'(always considering this is a one casting job').

"A Rush Order for Steel Castings" by R.G. Woolway, February 1908:

'Only one casting was required and the duplication of it not very likely...'

'The Patternmaking and Molding of a Steel Nozzle' by H.J. McCaslin, October 1909:

'As only one casting was required and its duplication not very likely...'.

'The Shop Practice of the Patternmaker' by W.S. Giele, September 1910:

'if only one casting of the kind in question is required...'.

February 1911, author not identified:

'if only one casting is wanted from a pattern...'.

BELTING

Belting was an American Journal published in Chicago but included an article from James Edgar entitled "Comparison of American and British Foundries' in its March 1922 issue:

"A one-off job can be most cheaply made by hand, but it would often pay to put a pattern on a plate for half a dozen castings."

THE PATTERN MAKERS JOURNAL

Finally in respect of these journals, and very briefly, I located a US journal originally published in 1896 called the 'Pattern Makers Journal' for which searchable copies are available from 1903. This journal, published in Philadelphia, was the official organ of the Pattern Makers League of North America and largely concentrated on social or League matters and didn't carry many articles on the craft of pattern making. I didn't find any relevant articles until 1928 and it's not worth reproducing those here.

COMMENTS ON THE JOURNALS

A couple of points worth mentioning about these trade journals.

Firstly, they often contain papers read at meetings which are followed by what appear to be careful transcriptions of replies by attendees at the meetings. In The Foundry, this includes meetings from the 1890s. Those who think that things people said in the nineteenth century have been lost to posterity, therefore, need to think again. We have records of what patternmakers actually said and spoke about in the 1890s, and in the first decade of the 1900s, and they didn't speak of "one off jobs".

Secondly, it is curious that although the American trade journals do contain references to "one off jobs" etc. a remarkably large proportion of them are by Englishmen. For some writers, it's impossible to know whether they were English or American. I'm fairly sure that foundry workers and pattern makers in the United States would have known what a one off job was during the early part of the twentieth century, but it certainly seems that the expression "one off job" didn't spread out into the language of the general population in the United States in the way that it did in the United Kingdom after the Second World War so that metaphorical expressions such as "one off instance" were unable to evolve into common usage in the US and probably wouldn't have been recognised by most Americans until the late 1990s or early 2000s, albeit that they are now a part of the American English language. This subject requires further research but it certainly makes me wonder if something on a British newsreel or on a popular British film or radio show in the late 1940s or early 1950s was responsible for Brits knowing what a "one off job" was, while most Americans didn't, and for the more creative, metaphorical use of the expression in the UK applying to people and events to blossom.

PRACTICAL PATTERN MAKING by F.W. Barrows

F.W. Barrows was an American pattern maker and a contributor to American Machinist. His book Practical Pattern Making, published in New York in 1906, contains some interesting passages:

'See this chalk-mark, '2off'? That means two castings wanted from this pattern.'

This should highlight to everyone what'1off' also meant at this time, i.e. one casting wanted from a a pattern, and the way it was used.

Some other passages from the book in which Barrows avoids talking about one off castings, which demonstrates that such an expression was unknown to him:

"You can well afford to spend more money on a pattern from which a hundred or a thousand castings are to be made than one from which you want but a single casting." 

"If you want a pattern for some repairing or experimenting about the shop, and only intend, perhaps to make one casting, you would not be willing to spend much time on it...one coat of varnish ought to do for a single casting, and then the new casting wouldn't look quite so much like a makeshift job."

"Tell him that it is a job from which but one or two castings are to be made, then let him do the rest, and my word for it the job will give better satisfaction, both in time and finish."

AN EXPERIMENTAL INSTANCE

It's easy today to think that "one off" could only have ever meant something done once. But this was far from the only meaning this expression could have had. In the Nottingham Evening Post of 4 September 1970, while discussing a feature on a television programme, it was said that the feature would be "what they call in the trade a "one off" - meaning an experimental feature".

At this time, "one off" hadn't yet been included in any dictionary, so if someone believed it meant something experimental they were entirely within their rights to hold that opinion

ONE LESS THAN

Another example of a different meaning of "one off" than unique can be found in this complaint from a George Luckhart of Logan about the use of the expression "one off situation", which was printed in Norman Ballatine's 'This an That' column in the Belfast News Letter of 5 June 1979:

"Another phrase that gets up my sensitive nostrils is the term "one off". I would have thought of appealing to you to condemn it out of hand when, to my horror, disgust and chagrin, before I got round to it didn't you use it your very own self. Since the phrase "one off" in ordinary parlance generally means "one less than" nobody who ever uses the phrase, for example (and they are legion) 'a one off situation', ever takes the trouble to say how many situations that particular one is less than."

So, for Mr Luckart, in ordinary parlance, "one off" primarily meant "one less than". He was irritated, therefore, to note the number of people who kept talking about "a one off situation" where nothing was less then anything else.

Luckhart's definition is similar to this definition of "one off" found in the Stirling Observer of 7 March 1939 written by someone who doesn't appear to have been familiar with the concept of a one off job:

"SMALL_BORE RIFLE SHOOTING

ONE OFF

Overheard on the Princes Street Drill range: - Member (who has pulled one outside the scoring rings) "That's what you call "one off." For those who don't know, "one off" means you have scored 99."

A CONTEMPORARY PHRASE

On archive.org I found the proof I'd been looking for that "one off" was regarded as a new expression in the Post-War period. I felt sure someone must have commented on the appearance of this new-fangled expression and, sure enough, someone did.

A 1996 book entitled The Herald Years reproduced columns written by experienced journalist Jack Webster for The Glasgow Herald from the 1980s. One of those was a column he wrote for the newspaper of 10 February 1986, when he was aged 54, entitled 'The Legend of Jim Rodger'. In that column he wrote:

"But the unmistakable figure of Jim Rodger was, to use the contemporary phrase, "one off", a legend of the Fourth Estate who carved for himself a position of power out of all keeping with his status as a journalist."

There we have a person from history, from the 1980s, literally talking to us to tell us that "one off" in 1986 was "a contemporary phrase". Webster, who had been born in July 1931, had lived in a period when there was no such thing as a "one off". The earliest example I've located in writing of a person being described as a "one off" is from May 1964 when Webster was 32. He thus probably only heard of someone being "one off" when he was middle-aged, hence he noted it as a contemporary expression, i.e. one which had only entered the language recently.

Together with the Anthony Phelps book, cited in my One Off Article, this is the most compelling evidence that "one off" was a post Second World War expression. There can't be any doubting it.

ONE (SWITCHED) OFF

A superb example of how "one off" would not in any way have meant unique to someone in 1888 can be found in the Journal of Gas Lighting Water Supply, Sanitary Improvement of 27 March 1888.

Any diary defender should try and control their emotions while reading this 1888 extract:

Calm yourself Thomas, settle down Jay.

So, yes, it says "one off" in the second sentence:

"My own experience goes to show that, even when the purifiers are large in area as regards the make of gas, they should not be less than three in number—that is to say, three working purifiers. When the plan of “one off” is followed, the current of gas being controlled by a centre-valve common to the series, but only capable of operating in rotation, this would mean a set of four boxes."

But it doesn't mean unique or anything like it.

What is being spoken of here is the fact that gas companies would historically employ a system whereby four gas purifiers would be worked in succession in a plant with three on and one off. Others would have all four on. Having one off would mean you were following a one off plan.

It's actually clearer when seeing the full extract with a different part underlined:

"My own experience goes to show that, even when the purifiers are large in area as regards the make of gas, they should not be less than three in number—that is to say, three working purifiers. When the plan of “‘ one off” is followed, the current of gas being controlled by a centre-valve common to the series, but only capable of operating in rotation, this would mean a set of four boxes. Since purifiers of greater capacity have been adopted, rendering the periods of changing a matter of weeks, or even of months, instead of days, the old fashioned plan of ‘three on and one off” has deservedly fallen into disrepute. "

If we go back earlier, to an issue of the same journal of 18 September 1883, we can break diary defender hearts with this otherwise beautiful advertisement:

"One Cockey’s Dry-Faced Centre Valve (16 in. Connections), to work four Purifiers (one off)."

When you think about it, the most natural meaning of "one off", if not to remove something or take something off, would be to turn something off, which explains why no one in 1888 would ever have spoken of or written about a "one off instance" to mean a unique instance. "One off" just doesn't naturally bear that meaning in any way.

Moreover, I would suggest that these examples also demonstrate (to the extent it needs to be demonstrated, which it doesn't) that "one off" simply wasn't in use to mean "unique" in the 1880s for surely it would have been too confusing to write about a "one off" plan if "one off" meant something other than having one purifier turned off.

ONE TIME INSTANCE

There's another issue I'd like to deal with which is the suggestion by diary defenders that James Maybrick could, with just a little creativity and originality on his part, have invented the expression "one off instance" based on the use in foundries of "one off" to mean a quantity of one.

I'm not going to quibble as to how Maybrick would have been familiar with such an industry-specific notation, let's just say he knew that to cast one item in a foundry, a pattern maker or moulder would speak of casting one off.

This still wouldn't have led him to coin an expression "one off instance".

The reason, or at least one of them, is due to the meaning of "off". We all know what it means, I guess, but just to confirm: according to the Oxford Dictionary, it is, "Used with a preceding numeral to represent a quantity in production or manufacture":

While one theory is that this derived from ticking items off a stocklist, I think it is more likely to refer to making one or a number of castings off a pattern. Either way, the word "off" added to "one" doesn't naturally produce an expression containing any meaning of "uniqueness" (as we've seen from the above meanings of experimental, one less than and one switched off). The problem is that we are now so accustomed to talking about one off events, instances etc. that it's hard to think about it in any other way as unique, singular or unrepeated. My point is that there's nothing natural or obvious about this.

To explain what I mean, let's say, hypothetically, that instead of people originally talking about 1 off, 2 off, 50 off etc. to denote quantities, they spoke of 1 on, 3 on, 50 on, perhaps because this was derived from an expression of casting one item on a pattern.

Now imagine you are a serial killer writing a diary in 1888 about hitting your partner (you bad person!) and you are somehow familiar with this practice of patternmakers. Is there any possibility that you would have written, "I hit my partner and said it was a one on instance"? Of course not. It's meaningless, even with knowledge of "one on" as a notation of quantity. And there's even less chance of you having said that to your partner after you did it. For, while rubbing their bruise, they would inevitably have responded: "What? One on instance? What are you talking about?". It simply wouldn't have made any sense.

BTW do not hit your partner.

And do not do serial killing.

Now if over a period of 40 years, people spoke of a "one-on job" to mean a unique and unrepeated job, you might start to feel comfortable talking about a "one-on instance" and "one-on event" and of saying about a unique person that they are a complete one-on.

If "on" is too similar to "off" for this example to be clear, just think of another preposition such as "at". It could have been a "one at job". But you wouldn't have converted the notation of a quantity of "1 at", from talk of "casting one at", and then created the expression "one at instance". It's just not how language works. And once we replace "off" with something else like "on" or "at" or anything else, it can easily be seen how ridiculous is the notion that Maybrick could have pulled the expression out of thin air with no one else known to have done anything similar beforehand or for the next 70 years.

However, there is one expression to mean unique which Maybrick arguably, and I stress arguably, could theoretically, and I stress theoretically, have used in 1888.

This is the expression "one time instance".

After all, the word "time" is itself an indication of...er...time.... um, sorry my brain froze there, let's just say time is, off the top of my head, the indefinite continued progress of existence and events in the past, present, and future regarded as a whole. No, cheeky, I didn't just steal that from the first dictionary result that came up in Google, how dare you.

But according to the dictionary (see below), "one time" is definitely synonymous with "one off".

Did the expression "one time instance" , or similar, exist in 1888, you might ask?

It's a good question.

According to the Oxford English Dictionary (entry for "one time" below), the first recorded instance in the English language of "one time" relating to a single occasion, done or used only once was in 1928, although I question the example provided because "one time" also means former, as in "one time resident of London". The expression "one time loser" (which is the OED's example from 1928) strikes me as having that meaning of something from the past. Alternatively, or perhaps equally, it might just mean someone who has "lost" once. Indeed, Green's Dictionary of Slang tells us that "three-time loser" can be found from 1908 and "five-time loser" from 1912. The expression "one time loser" just seems to be the same with another number. So the O.E.D. might have got it wrong but I don't argue with dictionaries.

Nevertheless, if we were to assume that there were no earlier examples than 1928, on that basis we would surely have some difficulty accepting that James Maybrick, writing in 1888, could have used the expression "one time instance", although I'm sure that diary defenders wouldn't have a problem with it because they don't care about evidence.

However, the evidence from both archive.org and newspapers.com which I also consulted on this point isn't quite as clear cut. While I've been unable to find any nineteenth century examples of "one time" being used to mean unique in Britain, I have found some in in American newspapers.

This is the earliest I dug up. It's from the New York Sun of 7 January 1894 referring to a performance of Ibsen's "Ghosts" at the Berkely Lyceum:

"A great deal of care in preparation was evident and for a one-time performance went on with unusual smoothness".

This is from the Olathe News of 11 April 1895 speaking of "a one time advertisement":

This is from a May 1897 publication entitled 'Primary Education which refers to a "one time offer":

This is from Printers Ink of 17 November 1897 referring to "a one time ad":

And here's similar from the Minneapolis Journal of 3 October 1899:

Although I wasn't able to locate any examples earlier than 1894, and no examples at all from the UK in the nineteenth century, it's hard to deny the possibility that someone in 1888 who had been to America might have heard or read the expression "one time instance" and used it after his return to England.

My goodness, can you imagine the fights if diarist HAD used the expression "one time instance"?

It would be difficult to say that James Maybrick couldn't possibly have done so. The diary defenders would have crowed with all their might that the diary had not only survived but it was both incrediiiible and amaaazing that any forger from 1992 could have known that "one time" was an American nineteenth century expression bearing in mind Maybrick's American connections. My goodness, we'd never have heard the last of it.

Thankfully, the diarist did not write "one time instance" so we don't need to worry about it, but the point remains that if James Maybrick wanted to create or invent an expression to indicate that he wasn't going to hit his wife again, surely it would have been "one time instance" which at least had a chance of being understood, not the opaque and weird (not to mention impossible) "one off instance".

There is another point about the use of "one off instance" versus "one time instance". Bear in mind that through the 1910s and 1920s the use of the expression "one off job" is very much confined to obscure technical trade journals, almost always in the context of a discussion about pattern making, not even being recorded by the Oxford English Dictionary as having been used until 1954, when it was spotted in the Architectural Review (with the very first dictionary record of "one off" as an expression being from 1934, within the phrase "one off pattern", in the context of Proceedings of the Institute of British Foundrymen).

It's kind of interesting, therefore, that we find this from the Salt Lake Mining Review of 15 March 1909:

"The expert knew that this was a "one-time" job".

And this in the Washington Times of 17 July 1914:

"Culling is not a one-time job, but should be repeated."

And this in the Boorowa News (an Australian newspaper) of 22 May 1925:

"the position of a Member of Parliament was a one-time job..."

And this in Public Opinion of 8 September 1919:

"a "one-time" man in a "one-time" job".

And this in The Florists' Review of 15 May 1919:

"When you do your glazing with Federal Greenhouse Cements it is a one-time job."

The Ottowa Journal of 9 November 1928 carried this advertisement:

"Make a one-time job of protecting your radiator against frost this winter."

And this in the Meridian Daily Journal of 13 October 1931:

Due to the word "time" being in the expression "one-time", it didn't need to evolve in the same way that "one off" needed to. We've already seen "one-time performance" from 1894 and there were plenty of other early 20th century early examples of "one-time" in newspapers (although not British ones).

Hence, we have "one-time sale" in the Cheyenne County Rustler of 24 December 1903:

And the Washington Evening Star of 11 July 1906:

And the Chicago Tribune of 29 November 1906:

And the US Birmingham Post Herald of 14 May 1911:

And the Toronto Republican of 26 December 1912:

A couple of other examples:

The Stockton Review of 10 February 1910 has "one-time event":

The Harrisburg Daily Independent of 12 January 1912 has the same:

You might be wondering if there are any early 20th century examples of "one time" in British publications. Not many is the answer. In the Derbyshire Times of 12 November 1921, the Mayor of Chesterfield was quoted as saying that people "would realize that the time had come when the Mayorality of Chesterfield was a one-time job".

It's not entirely clear if he was saying that the position of mayor was in some way a unique job, or something else. Tatler of 23 June 1926 carried a letter in its 'Letters from Evelyn' series which referred to the Ascot preparations as being "such a one-time job while it lasts":

Again, it's a little difficult to be certain of the meaning of "one time job" here and the same applies to the use of the expression "one-time job" in the Birmingham Evening Despatch of 17 October 1928:

"ONE-TIME JOB

"It's a one-time job, remember," said a Walsall magistrate to-day to a man who was granted a licence to keep a public house."

He might have been talking about the granting of the licence rather than the job of a pub landlord but it's not possible to be certain.

We do get clear examples of the use of "one time" to mean unique or unrepeated after the Second World War but not too many and one might ask why "one time" didn't really seem to take off either in America or, especially, the UK considering that it seems to make far more sense than "one off". I would suggest it's due to that horrible ambiguity where "one-time" also means "former". If you were to refer to a "one-time criminal", do you mean he used to be a criminal committing lots of crimes or do you mean he only ever committed one crime? You can't tell without the context. That's one possibility that occurs to me anyway.

A UNIQUE INSTANCE

Could James Maybrick in 1888 have told his wife that hitting her was a unique instance which would not be repeated?

It would have been a somewhat unusual way of putting it but the expression "a unique instance" certainly existed in the nineteenth century.

An early example is this one from the Lancet of 31 August 1839:

And this is from the year of the murders in the Spectator of 4 August 1888:

There are plenty of other nineteenth century examples - the British Newspaper Archive has over a thousand results for "unique instance" from that century - which just throws into sharp relief the complete absence of any examples of "one off instance" until the 1970s.

ONE OF A KIND

Finally, I want to consider another synonym for "one off" which is "one of a kind".

As proof of the two expressions being synonymous, there are plenty of twentieth and twenty-first century examples of people writing "one of a kind [or] one off" and vice versa. Some examples are:

Banbury Guardian, 28 November 1985

"Individually designed and made, each is a one-off, one-of-a-kind creation, perfect for any occasion."

Great Car Collections of the World by Edward Eves (1988):

"Many of the autos feature one-of-a-kind or "one-off" body styles which are considered individual works of automotive art."

This is from a 2001 book called British English A to Zed by Norman W. Schur which literally defines "one of a kind" as "one off":

And this is a useful thesaurus entry in the American Microsoft Encarta College Thesaurus (2002) for "Extraordinary: Uncommon" which includes all forms of synonyms for "one-off" including "one of a kind" (and which confirms that "one off" was regarded as a UK expression):

We find "one of a kind" used in the nineteenth century. For example, from American Machinist of 7 August 1886:

"This is for the reason that the amount which such an article did cost is a very poor index of what it would cost to build a second one, it is being usually the case that but one of a kind of is needed, and no duplicate has been made."

And American Machinist of 14 March 1889:

"In a previous article on this subject, a method for moulding such castings, when but one of a kind is wanted, was described."

So James Maybrick could have described hitting his wife as one of a kind, but it would have been very suspicious if he had said it was "a one of a kind", because that's not how the expression appears to have been used in the nineteenth century - although it was used this way in the twentieth century (and continues to be used this way into the twenty-first century), with some twentieth century references to "one of a kind jobs". Further, it would have been extremely suspicious if Maybrick had used the expression "a one of a kind instance". But perhaps not impossible, and one can find it in the modern era, hence, for example, from a 1986 magazine of the US Navy called 'All Hands" referring to "an isolated, one-of-a-kind instance":

It's another one that would have caused intense debate if "one of a kind instance" had been in the diary but thankfully it isn't. What is in the diary is the literally impossible "one off instance".

LORD ORSAM

27 June 2024