AI Enters the World of Antique Tool Collecting

 We live in world where AI is playing an ever increasing, potentially problematic role in our lives. It may be no surprise to many tool collectors, but several recent experiences have convinced me that this technology has the potential to significantly enrich our understanding of the historical characteristics and origins of many of our antique tools. This is especially true for “what’s it’s”, but even for tools that we feel we know quite a bit about.

I recently used Google’s Gemini AI tool to investigate the identity of a dozen of my “what’s its”. This involved posting a photo and letting Gemini have a go at it. I believe ultimately it was able to identify most, but not all of them. The program will sometimes offer several reasonable options and leave it to you to choose one. Often Gemini’s first suggestion is clearly wrong. The next step is key. You must come back at Gemini with a reason its description is likely incorrect and add additional characteristics of the tool in question which the program appears not to have paid attention to. Often the program will ask you specific questions regarding some aspects of the tool. This back and forth may continue for several rounds until an identification is provided that makes sense. At the end of each of Gemini’s paragraphs it usually provides a link to a source it has apparently utilized, or which may provide pertinent information. 

Another way that AI can be of use to antique tool collectors is its ability to expand one’s understanding of a known tool. The following is an example using a large pair of early European wing dividers in my collection. 

          

 Gemini was able to focus on a range of the tool’s characteristics. This discussion went on for quite a while and generated 11 pages of dialog when printed out.  The dialog began with a question I raised regarding the ways to distinguish between dividers from the 1600’s and those of the 1700’s. Gemini came up with five differences, summarized the comparison and provided photos and sources. I then brought in the example above to see what Gemini would say. 

        

 Above is the ball joint with a flared base characteristic of a 17^th century tool.        

 

          

 Simple end to the wing as opposed to the 18^th and 19^th century decorated end along with a “lorgnette” thumbscrew (round, flat head with pierced hole). The hole allowed the user to insert an iron rod (“tommy bar”) to firmly tighten the screw. 

           

 The unthreaded “through hole” on the backside of the thumb screw boss (housing) found on some early dividers is apparently a purposeful detail. It provided a way for shavings from early taps or later debris to escape as well as a way to remove a snapped thumbscrew. 

The program suggested an origin of these dividers from the Netherlands, Germany or England. When I questioned why France was left off the list it replied that I had caught a major omission and that, based on several of the detailed characteristics, the dividers were likely French and falling into the Louis XIV era from 1643 – 1715. 

           

 We then shifted to the fixed point of attachment of the wing. Instead of being riveted in place Gemini stated it was secured by a “hot weld”, a more complex 17^th century technique than the later use of a rivet.

 

          

 The top and bottom of the legs for three inches above and below the wing bosses are decorated with ogee/cyma swirls. This decoration and its location is apparently characteristic of the High Baroque period between 1660 and 1690. This further solidifies the dating of the tool.   

Decorations are hot forged not cold file work. This is associated with the late 17^th century.

The 21” length is typical of dividers used in timber framing, shipbuilding and millwrighting.

 

           

The program even explained the occurrence of an apparent forging accident that resulted in a “red-short split delamination” and the correction with a fire-weld repair.

After summarizing the tools characteristics and providing numerous references, Gemini offers to provide comparative examples.

 All of Gemini’s observations are drawn from existing information in on-line sources so, given enough time and motivation, you could probably generate a similar analysis without the use of AI. Google’s AI program simplifies this task significantly. You must maintain a critical eye on Gemini’s analysis since the complex algorithms rely on the validity of data from the sites it draws from and incorrect assumptions are certainly possible. In a later query regarding when wing dividers first appear Gemini claimed it was in the late 1500’s. When I brought up the painting entitled “God the Geometer” from the 1200’s the program claimed the wing on the pair of dividers God is holding was not a wing, but part of the orb being measured. I replied that the painting clearly showed a wing passing through the leg of the dividers and some form of adjustment knob on the other end. Gemini admitted that these were in fact wing dividers and thanked me for the correction.

 If used critically AI offers a powerful research option that can be used in many ways to increase our knowledge of the tools in our collections.

 Note: AI would probably have been more than happy to help write this blog or write it itself (which it didn’t). Also, beware as the program tends to flatter the person asking the questions and will even admit to using flattery when questioned!

 

 

A Common Design of Early Century English Friction Dividers

 In a recent post I outlined two often seen designs of early (18^th and early 19^th century) English wing dividers. One design I designated “Birmingham” the other “Lancashire” or Warrington”. In this post we’ll turn our attention to a common style of friction dividers for the same period. I currently have eight examples of the design below in my collection.

                                                                                       

 The title of this post refers to English tools, but as is the case with many hand tools of that period, several of these were likely made in Germany or other European countries utilizing designs popular in England and exported to that country. 

“Ogee Cone Joints” 

These dividers are typically five to eight inches in length and have the following characteristics: 

-        Filed ogee design on the upper legs with incised lines above and below the ogee

-        Short shoulders (just below main joint)

-        Five leaf, cone shaped main joint 

 

Five leaf joints have the advantage over three leaf joints of increasing the frictional surface area in the joint resulting in a joint that is more likely to keep a setting. I still marvel at the forging skill necessary to create a five leaf joint on a small pair of dividers.

In addition to the ogee design a “half moon (cyme) cone joint” variant is common and may be encountered more often than the ogee version.                                                                                          

 Of my eight examples only two are clearly marked as to a manufacturer. One of the half moon cone joint dividers has a “P.S.” stamped on the edge of an upper leg. These initials in early tools generally refer to Peter Stubs, a well-known Lancashire England toolmaker whose company produced tools from the mid-18^th century into the 19^th century. I would date this example to about 1790. A second example (the ogee cone joint photo above) is stamped T.H.B. & Co. for T. Hessen Bruch Co., a Philadelphia importer of high-quality German razors and tools from approximately 1873 to 1926. This points out that this design of friction divider was used over an extended period.

We'll end with an example different from the above. These are a fine early pair of probably German wing dividers that show fancy file work on the legs with some similarity to the designs discussed above. 

                                                        

 

 The Dividers of William Schollhorn and William Bernard 

The names Bernard and Schollhorn are known to many antique tool collectors as the patentees and manufacturers of a line of successful parallel-jawed pliers. Less well known, is that both were involved in the development of several innovative designs for dividers and calipers.

William Schollhorn (1834-1890), a German born machinist by trade, established a manufacturing operation in New Haven, Connecticut in 1870 with Frank Tiesing for the production of shears and scissors. After Tiesing’s death in 1888 the company’s name was changed to William Schollhorn & Co.

William Schollhorn’s Patents

During his lifetime William Schollhorn was awarded three tool patents, one for a corkscrew, one for dividers and one for a pencil holding attachment for dividers.

Jan. 9,1866

 William Schollhorn and Frank Pfleghar were awarded a patent for “An Improvement in Compasses and Calipers”. The two key elements of these dividers and calipers were a distinctive, sweeping, “triangular” wing to fix the legs and a tapered thumbscrew to lock the wing in place. These dividers and calipers were apparently quite successful as they often turn up in antique sales. The joint is typically marked “Wm. Schollhorn & Co., New Haven Ct.” and the patent date.                              

The pair of dividers shown below is similar to the standard 1866 examples above, but the hinge has brass caps and is without any markings. My guess would be that its an early model of the 1866 patent.                                        

 June 17, 1873

Schollhorn was awarded a patent for an “Improvement in Pencil Attachments” in 1873. This unit holds a pencil parallel to the leg of a pair of dividers. They are often found associated with examples of Schollhorn’s 1866 dividers, but they will fit dividers by other manufacturers if the lower legs are round. Both examples in my collection are marked with the patent date “Sep. 30, 1890”. Although the patent is labeled for its pencil attachment, the Directory of American Tool and Machinist Patents (DATAMP) does not show a patent for a pencil attachment on this date, so it is likely a re-issue of the 1873 patent 17 years after the original patent was issued. The 1873 patent also shows a modification of the 1866 patent dividers. The right-side leg includes a hinged lower section that can be moved by adjusting a screw at its top. This serves as a fine adjustment for the points. The top photo below shows an example of these dividers with a photo of the pencil attachment below.

           

William Bernard’s Patents

William Bernard (1848-1928) was issued over 100 patents during his lifetime, 56 of which are listed in the DATAMP, most of his tool patents relate to variations of his parallel jawed pliers. Bernard also received five patents for dividers all of which, along with his plier patents, were produced by Schollhorn & Co. Bernard became a Vice President of Schollhorn & Co.

May 6, 1890

Below is a later exampleof Bernard’s first plier patent. These pliers have been in production by various companies since 1890. Wm. Schollhorn & Co. was acquired by the Sargent Company in 1948. Several web sites focus entirely on Bernard pliers. The pair of pliers shown is marked “Sargent”.                              

July 19, 1892

The Bernard dividers based on this patent allow for the lower legs to swing up and fit within the upper legs enabling them to be carried in a safer and more compact fashion than most dividers. Bernard stated that unlike most dividers of the period which were either forged or cast steel these dividers were made of sheet metal which was lighter and less expensive to produce. The locking mechanism can, by means of a thumb screw, be made to move a bar within the fold of the upper leg which impinges and locks the joint. The leg opposite the locking leg carries an inch rule on both sides which was likely of questionable value. One side of the joint is marked “Bernards, pat. July 19, 1892” while the other side is marked “W. Schollhorn Co., New Haven, Conn.” This tool is far less common than the 1866 Schollhorn patent dividers pictured above.

                           

Aug. 7, 1900

Bernard’s second patent for dividers involves a side-locking mechanism to fix the triangular wing. A wing nut drives a shoe type locking brake against the bottom of the wing. This model includes a typical fine adjustment mechanism on the left side. The tool pictured below has the W. Schollhorn Co., New Haven Conn. mark on one side of the joint and “pat applied for” on the opposite side. Later examples include Bernard’s name and the 1900 patent date. Many also include the model name “Excelsior” stamped on the side of the leg.                   

           

Oct. 17, 1905 & Dec. 5, 1905

The final patents for dividers issued to William Bernard were for a relatively basic style tool with a slotted wing and a typical thumb screw lock and a fine adjustment screw on the left end of the wing. This model was stamped with name “LODI” on the side of the upper arm. The December 5 modification of this patent was for a spring for the fine adjustment. One side of the hinge on the example below bears the marking “W. S. Co New Haven Conn” and the other: “Patented Oct.17 1905” Below the October date in small letters is “Dec. 5, 1905”. No doubt due to its simplicity and resulting low cost this was apparently a popular tool which shows up quite often.                              

 

 

Common Styles of 19th and Early 20th Century American Wing Dividers

 

Common Styles of 19^th and Early 20^th Century American

    Wing Dividers

 

It is likely that most dividers and calipers found in this country in the 18^th and first half of the 19^th century were user or blacksmith made or imported from abroad, mainly England. American manufactured friction dividers are uncommon except for Osborne’s leather workers models. Most wing dividers and calipers manufactured in America during the last half of the 19^th century and on into the early 20^th century fall into a few broad style categories. The style names listed are my creations.

Straight-Legged

These dividers are relatively simple in design compared to the Birmingham and Lancashire models made in England with chamfering and designs filed into the legs (discussed in an earlier blog post). Characteristics include:

-        Straight legs usually square in the upper portion transitioning into a round section below.

-        Small round single/rule or occasionally, as with a Starrett, a three-leaved box joint. The joints on steel dividers were often faced with brass washers.

-        A characteristic fine adjustment mechanism usually consisting of a leaf spring attached to the inside of one leg and an adjustment wheel on the outside of that leg.

-        The wing held in place by a simple flat thumb screw.

Many of the earlier versions of this style were made mainly of brass with steel components and often had patented elements. Examples include dividers with Sullivan(1880), Miller(1873) and Stoddard(1872) patents.

Later versions were made of steel and were produced by well known manufacturers such as Stevens, Peck, Stow and Wilcox, Sargent and Starrett. Many of these were offered in graduated sizes and produced well into the 20^th century.

 

 

Bow-Legged

Similar in several respects to the straight-legged, the major difference of the bow-legged dividers was the design of the legs. The upper third or so came off at an acute angle from the joint then bent in so the legs were parallel to each other. The bend was sometimes pronounced, sometimes more gradual. Here again there were patented versions such as Weatherhead(1873), Cook(1871) and Copeland(1887). Later versions were offered by the same companies listed above that produced the straight-legged versions with the addition of Stanley. Both straight-legged and bow-legged models often came with replaceable points or pencil holders.

 

Slot-Winged

This later design was like the straight-legged style, but the central portion of the wing was cut out and pierced by the locking nut. These are often light weight tools which don’t seem to show the quality of the previous two styles. Manufacturers include Schollhorn(LODI) and General.

 I should mention that Schollhorn also made a very popular Bernard patent(1905) style of dividers that was not slot-winged as such, but had a triangular open wing.

 

A "New" Stoddard 1885 Patent Dividers Variation

In an earlier post dealing with the dividers of Oscar Stoddard, I mentioned that practically every example I have appears different in construction or marking from every other example. I recently acquired an example of Stoddard's March 31,1885 patent (right-hand pair above). In this patent the leg points pivot allowing them to remain perpendicular to the surface being measured. This is a fairly uncommon tool compared to Stoddard's 1872 patent, which is the one that usually shows up for sale.

These dividers have a number of issues including a missing fine adjustment spring, a replaced wing lock thumb screw as well as replaced locking thumb screws for the pivoting lower legs. Once again, the new example shows a number of differences from the more typical example (left in photo above).

                                                    "Old"                             "New"

 
The upper, square portion of the legs in the new pair is approximately 1/2" longer than in the old pair.The wing is 90 degrees as opposed to 180 degrees in the old example. 

 The markings on the upper legs also differ. The older pair logo above is a typical three line oval found in many Stoddard dividers marked "O. STODDARD, PATD MAR 31 1885, DETROIT MICH." The marking on the lower pair is faint, but the oval has two lines with the patent date above and O. Stoddard below, with a double diamond pattern in the center. None of my other Stoddard dividers have a similar marking.

                                                    "Old"                        "New"

The middle section of the legs on the old model above have locking thumb screws that allow the lower legs to be adjusted or removed. In the new model the two leg sections are permamently locked in place. In addition, the lower legs in the old example are steel while  they are bronze/brass in the new example.

So, the questions regarding the history of Oscar Stoddard's patented dividers continue to add up. Why so many variations? Who manufactured the tools for Oscar (at a later time they were manufactured by J. Stevens A&T)?

 

A VERY Old Pair of Wooden Dividers

 A recent purchase from a Fine Tool Journal auction brought home this very interesting pair of wooden wing dividers.

                                                    

They are most likely European and, I would argue, many hundreds of years old. They would seem to predate the 1700's, so I'm guessing 1600's or quite possibly earlier. A primitive tool of that time would be very difficult to date. They are 18.5 inches in height.

Here are some closer shots of the dividers.

                                    

The hinge has three leaves with a wooden pin. The tool shows extensive decorative elements which I suspect could be a hint as to its origin. There are traces of black paint and inactive "worm" holes visible in several areas. I'm unsure of the wood type, but it is not oak.

                

The wing is iron with a wooden pin holding it to the left hand leg. There is currently no means of locking the wing in place, but there is space for a wedge where the wing passes through the right hand leg.

                

The wrought iron pins at the bottoms of  the legs show evidence of the blacksmith's hammer. They are held in place by iron ferrules.

Excuse my wishful thinking, but might this guy even be of medieval origin??

Any thoughts or insights greatly appreciated.

 Two Dominant Styles of Early English Wing Dividers.

 

 

Up until the post-civil war era most, if not all, manufactured dividers and calipers in this country were imported from England or continental Europe. Since the early 1600’s English factories and their cottage industry suppliers dominated the production of small tools (sometimes referred to as “toys” in catalogs). Two English centers for the production of dividers and calipers were Birmingham and cities in the county of Lancashire, such as Warrington. The wing dividers produced in these two centers during the late 18^th and early 19^th centuries have easily distinguishable characteristics that allow us to assign many tools to one of these production centers.                              

 

Birmingham Pattern 

                                              

 To my knowledge, dividers in this category have never been assigned a name, so I’m calling them the Birmingham pattern. These tools have six consistent characteristics that set them apart from the second category: 

-        flat, three-leaf, rule joint

-        concentric circles incised on both sides of the joint

-        one or two angled incised grooves at the top, back and sides of the leg shoulders just  below the joint

-        curved chamfers on the shoulders of the dividers above the wing

-        triangular legs in cross section

-        hip bosses (carrying the wing) with angled sides due to the chamfers    above and the triangular legs below 

Four of the eight examples in my collection have heart-shaped (“mouse ears”) wing locking nuts. Six of the eight have a decorative tip on the end of the wing. Six of the eight have wings that sweep to the right, two to the left. All are of medium size, ranging from 8.5 to 16 inches. 

Three of the four marked dividers are by known Birmingham makers: W.&C. Wynn, Benjamin Freeth and Sam Ault. Ault was active between 1767 to 1781, so this style of dividers was made since at least the mid 1700’s. The fourth pair is marked “Walker”. The Directory of American Toolmakers lists a T. Walker as making dividers in America with no dates or location given. It is possible that this is an error and the maker was, in fact, English or that Walker was American and copied the Birmingham design. A pair of Walker-marked dividers almost identical to my example appears as Fig. 13 in Kebabian and Witney’s classic American Woodworking Tools.   

Birmingham dividers appear cruder in construction compared with the Lancashire dividers described below. Possibly this resulted from their being forged from wrought iron or poorer quality steel. 

 

Lancashire (Warrington) Pattern 

                                            

 “Lancashire” is a descriptor that has been applied to tools from this English county including hacksaws, spring dividers and calipers (Salaman, Dictionary of Woodworking Tools). Dividers of this type sold in England by current tool dealers often carry the label “Warrington dividers”. Warrington is a city in Lancashire. 

The following are characteristics that distinguish these dividers: 

-        cone-shaped hinge faces

-        a flattened section of the shoulders just below the hinge

-        flat chamfers on the lower shoulders with straight sides (except the smallest examples)

-        boxy hip bosses, most with raised “pyramids” on the left side of the boss

-        wings sweeping right, usually without a decorated tip

-        simple, flat, oval wing locking nuts

-        square upper and lower legs (often with slight chamfers) 

Eight of the ten examples in my collection are marked with makers names. Three of these are Warrington makers: Thewlis, Plumpton and Edelstein & Son. My examples range in size from 6.5 to 16.5 inches. Smaller dividers of this period were typically friction rather than wing dividers. 

 Lancashire style dividers were also made in Germany and France and exported to England and the United States. The German examples I have by T. Hessen Bruch and Regenstein & Maller are finely crafted pieces exceeding, I would argue, the English pieces in workmanship. 

The Lancashire dividers in my collection all appear to date to the 19^th century and are made of steel while many of the Birmingham examples show mid to late 18^th century construction and appear to be made of wrought iron. Only two of my collection of Lancashire style dividers have a fine adjustment mechanism for the wing (see below), while none of the Birmingham does.

 

A Few Exceptions to the Generalizations Above 

Not surprisingly, early wing dividers often don’t fall cleanly into one of the above categories. They show elements of both the Birmingham and Lancashire patterns described above or neither. The two dividers pictured below are primarily Lancashire style, but the joint shape and chamfering are atypical.

 

                              

 

 The wing dividers shown below are by Joseph Fenn, a London maker active between 1821 and 1873. They are basically a Lancashire style tool, but with the addition of a fine adjustment wing nut on the end of the wing. Not clearly visible in the photo is a thumb screw on the backside that locks the fine adjustment in place.

 

                                         

 

George Plumpton was a Warrington maker active likely in the late 1800’s. The dividers pictured below are typical Lancashire/Warrington wing dividers, but with a rack wing mechanism that acts as a fine adjustment. This type of dividers is uncommon and difficult to find in a functional state with unbroken teeth on the wing.

                                        

 

Additional Sources:

Tools For The Trades and Crafts (Pattern Book), documentary by Kenneth D. Roberts,  Ken Roberts Publishing, Fitzwilliam, NH, 1976.

Drawing Instruments, 1580-1980, Maya Hambly, Sotheby’s Publications, London, 1988

Tools, Working Wood in Eighteenth-Century America, Gaynor & Hagedorn, Colonial Williamsburg Foundation, Williamsburg, 1993