Last updated 8 June 2024, David Green
I had always believed that Amsler numbered his polar planimeters with just one sequence of serial numbers, no matter whether they were the Type 1, 2, 3, 4, 5 or 6 models, or they were sold through resellers such as Elliott or Stanley in the UK, Morin in France or Crosby Steam Gauge and Valve Co. in America. The very useful table developed by Peter Hopp and Joachim Fischer dating Amsler's serial numbers implies the same belief.
However, several "Amsler" planimeters appear to buck the trend.
The first hiccup is that two "Amsler" planimeters with serial number #5 exist. One is exhibited on the web site http://anklick-bar.de/matheprojekt/planimeter-ur.jpg. The claim that it is the oldest surviving polar planimeter cannot be disputed.
The other serial number #5 is more developed although clearly still an early design. With just one discrepancy in the numbering, one might wonder if it is simply an engraving error. But I have almost identical planimeters, serial numbers #9 and #338, even though planimeters #543 and #582 both resemble the earlier planimeter-ur.
So what is going on? I had wondered if Amsler started a second series of serial numbers shortly after he started production, perhaps when the rectangular cross-section pole arm replaced the circular cross-section, or perhaps when he took over production from Goldshmid and Kirchofer.
But apparently not. Following correspondence with Dr Joachim Fischer and Peter Hopp, this is my present understanding. As a resident of Australia who speaks no German, primary sources are pretty much beyond my reach. What follows is my interpretation of secondary sources, actual planimeters appearing mainly on Ebay and advice from Dr Fischer and others. Any errors are due to my misinterpreting this information.
Jakob Amsler-Laffon was a mathematician, physicist, engineer and the founder of his own precision engineering workshop. He was born 16 November 1823 in Stalden bei Brugg, canton Aargau, Switzerland and died 3 January 1912 in Schaffhausen, Switzerland.
His father Jakob Amsler was a farmer, his uncle Samuel Amsler a well-known engraver. After attending the local school in Unterbözberg and the district school in Lenzburg, Amsler graduated from the canton school in Aarau in 1843. During 1843-44 he studied theology in Jena, but turned to mathematics and physics during his studies in Königsberg in Prussia (1844-48). Amsler gained his doctorate from Königsberg in 1848.
He returned to Switzerland in the same year, worked at the observatory in Geneva for a year and qualified as a lecturer in mathematics at the University of Zurich in 1849. Later in that year he accepted a position as a mathematics teacher at the grammar school in Schaffhausen, where he worked from 1851-57. Having completed his studies at Zurich he published papers on mathematical physics, in particular on magnetism, heat conduction and on the attraction of ellipsoids.
In Schaffhausen he met the pharmacist's daughter Elise Laffon (1830-1899), whom he married in 1854 and whose family name he added to his own. The couple had two daughters and three sons.
His oldest son Alfred Amsler (1857-1940) was a mathematician and engineer in his own right and succeeded his father as the owner and director of their factory. From about 1885 until about 1905, father and son closely cooperated on many projects in their business; many of their ideas, inventions and constructions of the time are difficult to attribute to either one of them. In 1867 the Swiss Army introduced breech-loading rifles based on Amsler's plans.
In 1858 Jakob gave up teaching and started his own company. In addition to planimeters, it also manufactured integrators, hydrometric measuring devices and other precision instruments. From 1886 on, Amsler successfully turned to the manufacture of materials testing machines.
The timing of events after 1854 is rather uncertain. There are various claims, some of them conflicting.
* note: Charles T. Amsler, a Swiss immigrant, and possibly a relative of Jacob Amsler, began to sell European instruments in Philadelphia in 1848 and briefly partnered with A. H. Wirz from 1855 to 1857. In 1861 C. T. Amsler sold his business to William Y. McAllister and returned to Switzerland. [https://americanhistory.si.edu/collections/search/object/nmah_904556]
In a flyer dated 1856 Amsler & Wirz used the following illustration of Amsler's planimeter.
In his catalogue dated September 1867, McAllister, of 728 Chestnut Street, Philadelphia, Pa., used the same figure.
SerNo. Marked Manufacturer Date Source
5 type 3 Amsler 1854 planimeter-ur
5 type 3 Blankenburg unknown David Green collection
9 type 3 Blankenburg? unknown David Green collection
? ? unknown Ebay August 2017
83 type 1 Amsler 1855 Bob Otnes collection
213 type 3 Amsler 1855 Mathematische Instrumente collection
276 type 3 Dennert & Pape unknown Ebay March 2019
326 type 3 Dennert & Pape unknown Ebay June 2022
338 type 3 Blankenburg unknown David Green collection
424 type 3 Elliott Bros Amsler 1856 Science Museum, Peter Delehar SIS 35
543 type 3 Amsler 1856 Mathematische Instrumente collection
569 type 3 1856 private collection
582 type 4 Amsler 1856 Mathematische Instrumente collection
? type 1 Amsler 1856? UKSRC Newsletter No 24
783 type 3 Dennert & Pape unknown Ebay June 2019
828 type 3 Dennert & Pape unknown private collection
849 type 3 Dennert & Pape unknown Ebay June 2022
1018 ? 1857 Ebay Jan. 2014, mentioned in Hopp-Fischer list, no info
1064 type 3 Amsler 1857 Ebay July 2020
1984 ? 1859 mentioned in Hopp-Fischer list, no info
2108 type 3 1860 Ebay Apr. 2012, mentioned in Hopp-Fischer list, no info
2125 type 1 Amsler 1860 private collection
2185 type 3 Amsler 1861 David Green collection
2374 type 6 Crosby Amsler 1862 Ebay Apr. 2014, mentioned in Hopp-Fischer list, no info
2501 type 3 Amsler 1862 Ebay October 2021
2503 type 2 T.B.Winter Blankenburg? unknown Drawing Instruments Group gallery
3018 type 2 Casartelli Blankenburg? unknown Drawing Instruments Group gallery
3041 type 1 Elliott Bros Amsler 1864 Ebay April 2001
3145 type 2 Elliott Bros Amsler 1864 Ebay February 2017
3385 type 4 Amsler 1865 Ebay June 2020
3691 type 4 Amsler 1865 CNAM
3742 type 2 Amsler 1865 todocoleccion
Two "Amsler" planimeters with serial number #5 exist. One in the Deutsches Museum, shown below, is exhibited in the web site organised by Barbara Haeberlin and Stefan Drechsler (http://anklick-bar.de/matheprojekt/planimeter-ur.jpg).
So far as I can see it is an exact match to Amsler's 1856 drawing (below). Dr Fischer reports that it "was given to the Museum in 1906 by Amsler himself". The claim that it is the oldest surviving polar planimeter cannot be disputed.
Amsler's original concept is illustrated in his book published in 1856.
The other serial number 5 is more developed and is shown later.
Clearly this is a usable planimeter but Amsler soon tweaked the design to improve performance or to simplify production. During the production of the early planimeters shown above, several changes were made:
This planimeter was sold on Ebay in August 2017.
The seller provided a rather odd collection of photos and the following composite picture is an attempt to show it in one piece. It has the cube connection of the pole to the pole arm, the tapered connection of the pointer and a small counter wheel, like sn #5.
It sold on Ebay for $113.50 in August 2017. If this is an Amsler product it would seem to be earlier than serial number #83. Someone got a bargain. The American seller refused to take international bids. Serves him right.
However ... the two-piece, screw-on pointer is odd. The box is supplied with two, what look like, calibration plates. Were these introduced this early? And the case has a silver border, not unlike the Blankenburg cases. I am not convinced this is a genuine Amsler.
This planimeter was first mentioned in an article by Bob Otnes in 2002.
The planimeter is unique in this short list of planimeters because it has a fixed length tracing arm. In that regard it is a precursor of the later Models 1 and 2.
The only difference from the original drawing appears to be the way the pole is connected to the pole arm.
Its case has a push button latch.
This planimeter is also in the Mathematische Instrumente collection. It's web page shows thirteen nice photos.
This planimeter was sold on Ebay in October 2021.
[Drawing Instrument Group message #9252, 15 May 2022
... To follow up, I did buy the Elliott planimeter discussed, and it is number 569 ... with an
Elliott London
signature on it.
]
Amsler seems to have had some difficulty deciding the best way to fix the counting disc and the configurations vary somewhat. This curved variation is quite extreme. But it is marked Elliott, who was Amsler's agent in the UK, so presumably it is a genuine Amsler.
A third early Amsler planimeter in the Mathematische Instrumente collection. There are sixteen photographs in the web page here. It appears to be longer than serial number 543 and perhaps is a precursor of the later type 7 model.
It isn't clear where this fits in - the serial number is not known. It was noticed by Peter Hopp at the London Scientific Instrument Fair in 2011. Where it is now nobody knows, but fortunately Peter took a photo.
This Amsler Type 1 is about 5¼" long in a 6" case compared to the more usual 7" device in a 9" case. It is shown next to an English £1 coin for comparison. 10118 is the scale factor, not the serial number.
The first mention of a type 1 planimeter appears to be in Dingler, Band 140, 1856. The accompanying plate is shown below.
The UKSRC Newsletter No 24 has a better copy of Figure 3:
This looks as though it may be a conceptual design rather than a drawing of an actual model. Elliott Brothers published a pamphlet with a drawing of the planimeter but it is not dated.
However, W. Davis Haskoll, in his book "The Practice of Engineering Field Work" published in 1858, provides Figure 145 shown below, and mentions (page 308) that "This instrument, illustrated in Fig 145, and lately introduced by Messrs. Elliott, has already been received with a great deal of favour."
It takes a while to publish a book, so this dates the design to no later than 1858 and quite possibly to 1857 or even 1856.
The next type 1 planimeter in captivity is #2125, which dates to about 1860. The tracing pin is a clearly
different design so not many of the earlier model could have been made. This photo, with several more, was
posted in the Drawing Instruments Group's gallery by Alan Williams.
(https://drawing-instruments.groups.io/g/main/photo/239271/2888827 to 2888829)
It is interesting that this type of pointer fitting was later used by Dennert & Pape, but not by Amsler, in their Type 3 and Type 4 planimeters.
The second serial number #5 is more developed although clearly still an early design.
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With just one discrepancy in the numbering, one might reasonably wonder if it is a simple engraving error. But I have two almost identical planimeters, serial numbers #9 and #338, see below.
It seems that these planimeters, and #9, are close copies of Amsler's design made by A. Blankenburg of Berlin. Little is known about Blankenburg. Even his Christian name "A." is a mystery.
I am indebted to Dr Fischer for the following:
"Blankenburg was a kind of early "OEM" manufacturer, but without being authorised by anyone. The origins of
"A. Blankenburg" are unclear; the first written report of the enterprise is known to be in 1879, but in one
instance it is supposed to exist since about 1864. A real problem between Amsler and Blankenburg occurs only with
the early instruments of both manufacturers, and there basically only with their models 3 (brass) and 4 (nickel
silver). In the case of the "second" #5 and serial #338, the problems is relatively easy to resolve, as the cases
still exist: If you find a silver rim on the lower part of the case (and mostly a different lock between the two
parts), it is a Blankenburg. So the "second" #5 and serial #338 are Blankenburgs."
In Thomas, Rupp, Scheurle (eds.): "Dynamical systems, number theory and applications: a Festschrift in Honor of Armin Leutbecher's 80th birthday" (see https://de1lib.org/book/17401921/e52f20) on page 6, Dr Fischer mentions that A. Blankenburg manufactured about 7500 instruments before WW I.
And Detlef Zerfowski adds this reference: Already in 1879, Blankenburg was manufacturing planimeters. They were exhibited in the Berlin Trade Exhibition in 1879. In the "Deutsche Bauzeitung" 1879, No. 93, page 476 it is mentioned: "Polar planimeter of well-known design by Bamberg, Blankenburg and Sprenger have been shown...."
This is a bit worrying. I have never seen either a Bamberg or a Sprenger planimeter. Does this comment imply that they were also, perhaps indistinguishable, clones of the Amsler models?
Also concerning is that serial number #9 is in an Amsler-style box rather than a "typical" Blankenburg box with a silver rim. As is serial number #2503. So the style of box cannot be relied upon to distinguish between the two makers.
This planimeter has a wheel locking attachment, shown in more detail here.
The following is extracted from "Integrating Instruments by Dennert & Pape" by Joachim Fischer, a chapter in "Dennert & Pape ARISTO 1872-1978" by Karl Kleine and Klaus Kühn.
"In the years 1997-1998, an American collector acquired two unmarked planimeters, which after careful comparison with other instruments and illustrations were determined to be Dennert & Pape products." The two almost identical instruments are numbered 276 and 783. Number 276 is shown above.
"For the time from 1862 (when, on July 1, the mechanic Carl Plath (1825-1910) sold his workshop to his co-worker J C Dennert) until 1930 there exists a list established by Georg Dennert in 1978, which correlates serial numbers with the year of delivery. ... For various reasons this list should be treated with a grain of salt."
"According to this list ... the planimeter No. 276 should practically stem from 1862. The first price list of Dennert & Pape from 1872 already mentions planimeters; the accompanying text always remains the same in the following years; the price list of 1882 has an illustration which almost exactly resembles these two instruments 276 and 783 - all these observations make the above conclusion all the more plausible."
In "the case of the planimeter No. 276 ... 1862 is a very early year for the start of planimeter production (compare Haff, being able to prove with their own order and invoice books the beginning of production to be 1863, which again makes their starting year of 1862, quite plausible). Should the dating of the instrument by means of the correlation list be half way correct, one must assume that Dennert & Pape started planimeter production right at the beginning of the company's existence, and also that the company thus belongs to the earliest manufacturers of such instruments - obviously based on the design of Amsler's instruments."
"The first known illustration of a Dennert & Pape planimeter is found in the price list of 1882. The illustration shows the planimeter with the adjustable tracer arm ... complemented with two orthogonal cross sections of the tracer arm: one parallel to the tracer arm through the tracing pin and the other at an right angle across the back of the bearing of the measuring cylinder. This drawing remains in the price lists/catalogs unchanged up to and including 1902."
"The cross section shows a very characteristic construction detail not to be found with other manufacturers: the sleeve of the tracer arm and the mount of the measuring cylinder consist of two flat pieces screwed together, while usually they are produced as one piece."
#783 was offered on Ebay in June 2019, #828 is adapted from a photo posted in the Drawing Instruments Group gallery and #849 was offered on Ebay in June 2022.
There is no risk of mistaking #828 or #849 for early Amsler planimeters - the white wheels date them to much later. The Slide Rule Museum notes that "Ivorine is the Dennert and Pape (Aristo) brand name for the white celluloid plastic they introduced in 1886 to laminate wood slide rules as a better material than wood for the inscription of scales. ... Other manufacturers soon followed suit." Presumably ivorine replaced the metal wheels in their planimeters at about the same time.
I don't quite know what to make of this planimeter. It was sold on Ebay in July 2020. It looks like an Amsler and the box looks like an Amsler box, but the pole arm is upside-down, and there is a very unusual lever by the counter disc.
Close up photos show that this lever serves to clamp the counter wheel, thus locking both wheels.
Noting that the figures on the tracer arm are upside down, it seems likely that this is a genuine Amsler that has been modified and, sadly, lost its rolling wheel.
Photos of #2503, retailed by T. B. Winter of Newcastle-on-Tyne, and #3018, retailed by Casartelli of Manchester, are from the Drawing Instruments Group gallery.
These three planimeters epitomise the difficulty of identifying the manufacturer. Superficially they are the same, but while #2503 and #3018 appear to be identical, the Elliott has some subtle differences.
(a) the socket for the measuring wheel axle fits flush in the Elliott, protrudes in the Casartelli.
(b) this screw on the Elliott looks smaller
(c) on the Elliott, the pointer to the counter disc is distinctly different, rounded at one end and more sharply pointed at the other.
(d) also, the grip for the tracing point is spherical on the Elliott but has a pointed top on the Casartelli.
Elliott was the officially appointed agent for Amsler in the UK, so one might assume #3145 to be a genuine Amsler. The Casartelli differs in several respects and has what looks like a Blankenburg box, so probably it was a Blankenburg manufacture. The Winter planimeter is identical with the Casartelli although it is in an "Amsler" style box, so presumably also made by Blankenburg.
Offered on Ebay in April 2001. Signed Elliott Bros. This appears to be identical with #3018.
One of the "Instruments d'intégration conservés au Musée des arts et métiers", described here.
Currently for sale on todocoleccion.
All these planimeters are slavish copies of Amsler's design. Not much risk of mistaking them for early Amsler products though: they all have white celluloid wheels, include the later features shown in Amsler's 1935 catalogue, and engrave their names on the planimeters.
This next planimeter is engraved with "Kent" The seller remarked that it was made in Japan in the 70s by Uchida but the only indication of this is a Japanese (?) logo on the box.
Miller received a patent for a polar planimeter independently of Jakob Amsler and in the same year (1855), but in contrast to Amsler only wrote about it later. Miller's design had the advantage of already being a compensation planimeter.
A little about Miller, extracted from:
NEUE DEUTSCHE BIOGRAPHIE
HERAUSGEGEBEN VON DER HISTORISCHEN KOMMISSION BEI DER BAYERISCHEN AKADEMIE DER WISSENSCHAFTEN
SIEBZEHNTER BAND (my translation)
NEW GERMAN BIOGRAPHY
PUBLISHED BY THE HISTORICAL COMMISSION AT THE BAVARIAN ACADEMY OF THE SCIENCES
SEVENTEENTH VOLUME
Albert Miller Ritter v. Hauenfels, mining scientist and entrepreneur, born 1818 Täpiöszele (Pest County, Hungary), died November 5, 1897 Graz.
After M. finished high school in 1839 with very good results, he joined the k. k. Main Mint Office in Vienna. In 1841 he moved to Salzberg as a shift foreman. In 1847 he was appointed professor for descriptive geometry, building science and drawing at the Bergakademie Schemnitz. In the course of the Hungarian Revolution of 1848, M. asked for a transfer to the Montanlehranstalt in Vordernberg (Styria).
In 1856 he published his "Lectures on the Art of Mining" in print. His mining-related publications cover all mining disciplines with many fundamental works, from the relevant geosciences to technical mining subjects including mining safety to mining economics. M.'s essays had a decisive influence on the development of mining in the Austro-Hungarian monarchy in the second half of the 19th century. M.'s other publications deal with fundamental questions of mathematics, natural sciences and technology, such as 1890 "The gliding of birds and the sailing aeronautics".
M. was a diverse expert, but also worked with direct responsibility in practice. In 1857/58, for example, he rehabilitated the large lignite mine Leoben-Seegraben, which was in difficulties due to a fire in the pit. From 1861 to 1867 he was works manager of the chrome ore mine in Kraubath. However, his entrepreneurial interest was primarily for the top echelons graphite deposits. The Sunk (Hohentauern) graphite mine he started in the early 1870s is still in operation today.
In a paper presented on 28 April 1885, Professor H S H Shaw mentioned that "A recent minor improvement has been to fix a locking spring to the frame, so that the roller can be held when the planimeter is raised for the purpose of reading it."
This probably refers to the clamp devised by Druitt Halpin and reported in "The Engineer" as "Halpin's Planimeter". Unfortunately the best drawing of it I can find is small and not very clear.
"The engraving shows a simple form of locking gear which has lately been devised for Amsler's planimeter, and which is now being introduced by Messrs. Elliott Bros of 449, Strand. The locking gear consists of a spring C, one end of which is T-headed, and which is fastened to the instrument by the screws already there for another purpose, and of a wedge-piece B sliding on this spring. As this wedge-piece B is made to travel backwards and forwards on the spring by means of the button fixed onto it, it bears on the back piece A and so causes the nose of the spring to rest on the edge of the wheel which traverses the paper. When this takes place, of course the travelling wheel is no longer able to revolve."
"The advantages claimed for this locking gear are that the instrument can be read with much greater facility ... In using the instrument it can be taken to the light and set at zero, and locked; it is then placed in position on the paper, ready to take the diagram, and unlocked, run over the diagram, and locked again, when it can be taken up from the paper without fear of losing its correct registration, and read conveniently in any suitable light."
"One of the chief uses, however, which mechanical engineers make of the planimeter is to measure the mean pressures on an area of engine diagrams. ... on trials when very large numbers of diagrams are taken, and have each to be calculated ... the instrument is set to zero and locked; the first diagram is then put under it, the locking gear opened, the diagram run over, the instrument is locked and the diagram taken out and the second diagram is put in place, the instrument unlocked, the diagram run over and the process repeated as before. In this way ten diagrams are taken, and the decimal point at the last reading is put back one place; by this means it will be seen the liability of clerical errors arising in the addition is greatly lessened, and the otherwise unknown value of the last decimal place is carried forward."
I haven't seen a real example of Halpin's clamp but a similar spring-operated clamp is shown in these photos of the locking mechanism on the Blankenburg serial number 9.
Halpin was unhappy that reviews of his locking device generally emphasised the improved ease of reading the numbers on the roller and not the purpose for which he intended it. At the Meeting of the Institution of Civil Engineers in 1886 he explained: "...the Author referred to one of the minor improvements by putting a locking-spring to the frame. Mr. Mair had noticed the great difficulty there was in reading the instrument, on account of the small scale to which it was graduated, but the Author had not completely followed the idea of adding the locking arrangement. The convenience of reading the instrument was doubtless very great, for it could be taken up and put in a good light, but the real object of the locking gear was to make the instrument do its own addition, and also carry over the decimal places now lost. Instead of taking each diagram by itself, and writing down the result of each separately, and adding them up, the instrument was set at 0 and locked; the instrument was run over the diagram, and it was locked, and so on. So that by taking ten diagrams successively, and putting the decimal point one point back, the instrument was made to do its own addition. It had the further advantage that, whatever the last decimal might be, it was carried on by the instrument. If it was 2.38, it could not be said whether it was 2.389 or 2.381".
Below are close-up photos of the mechanism on #1064. The principle is slightly different: when the lever is moved forwards it engages with the counter disc, thus locking both wheels.
The following illustration is in the Keuffel & Esser Co. catalogue dated 1881 although the same drawing is in the 1875 catalogue. It appears to show a similar lever.
Amsler provided a different solution for the same purpose.
The early Amsler models as they had evolved by the time of the 1935 catalogue.
The Mathematische Instrumente collection has this planimeter, serial number 8164, and it's web page shows thirteen nice photos. They believe the planimeter dates from about 1870. The Hopp-Fischer table puts the date closer to 1877. Amsler's brochure dated October 1868 has an illustration of this model. The Hoop-Fischer table indicates that some with serial numbers less than about 5500 would have been made by that date.
Amsler's instructions for using the planimeter, from an undated brochure, are shown below.
The Hopp-Fischer table mentions #2374 and #4440 as type 6 planimeters but provides no more information. The earliest documented example I can find is #8091, shown below. Amsler's brochure dated October 1868 mentions this model. The Hoop-Fischer table indicates that some with serial numbers less than about 5500 would have been made by 1868.
Amsler's instructions for using the planimeter, from an undated brochure, are shown below.
The Mathematische Instrumente collection contains a formidable selection of planimeters including one made by Jakob Goldschmidt. Their web page shows thirteen fine photos. So Goldschmidt continued to make planimeters after Amsler ceased to use him as a source, or perhaps restarted when Amsler's patents expired. The design is substantially different from Amsler's so they are easily distinguishable.
This very elegant Amsler-like planimeter was sold on Ebay on 7th June 2024. The seller suggested it was perhaps an Amsler one-off or prototype dating back to the mid 19th century. We have no way of knowing for sure but the construction details are quite different from known early Amslers and do not match any model I can recall.
The planimeter has no maker's name or serial number. However, there is a logo/trade mark, shown below. Can anyone please help identify this logo?
1. "Über die mechanische Bestimmung des Flächeninhaltes, der statischen Momente und der Trägheitsmomente ebener Figuren insbesondere über einen neuen Planimeter", Jakob Amsler-Laffon, 1856. Free download here.
2. "Improvement to Planimeters" by D. Halpin, Engineering, 31st October 1884. p. 141.
3. "Mechanical Integrators Including the Various Forms of Planimeters" by Henry Selby Hele Shaw, 1886 (reprinted from the Proceedings of the Institution of Civil Engineers). Download here.