On 11 October, The American Astronomical Society had an article on its website by Teresa Wilson (Michigan Technological University) title, This Month in Astronomical History: The Invention of the Telescope that is liberally strewn with easily avoidable errors.
We start off with:
The inventor of the refracting telescope is unknown, but the accomplishment is often attributed to the man who first filed a patent for it: Hans Lippershey (or Lipperhey), a 16th century Dutch eyeglass maker and inventor from Middelburg.
Although both variations turn up in the literature, historians of the telescope are clear that the man’s name was Lipperhey and not Lippershey, however he was German, born in Wessel, and not Dutch although he lived in Middelburg in the Dutch province of Zeeland. We continue:
Incidentally, the stories of his inspiration for building the instrument vary and tend to discredit his originality. In one scenario, two children were playing with optical lenses in his shop and he overheard them remark that a distant weather vane appeared closer when they looked through a pair of different lenses. In others, he took credit for the work of his assistant, or stole the idea from a third party altogether.
All of the above are fairy stories, which have no basis in history so why bother to mention them at all? And further:
Regardless of how events transpired, Lippershey filed for a 30-year patent from the States General of the Netherlands on 2 October 1608, creating the first written record for an instrument “for seeing things far away as if they were near.”
The first written record of the telescope is in the letter of introduction written for Lipperhey by the Council of Zeeland to Zeeland’s delegates at the States General, dated 25 September 1608. The quoted description of his telescope is actually from this letter.
Only weeks later, a lens maker from Alkmaar in North Holland, Jacob Metius, applied for a patent on a similar design. Zacharias Jansen, another eyeglass maker from Middelburg and purported inventor of the compound microscope, is also claimed to have invented the telescope.
Since the work of Huib Zuidervaart made public in 2008 and published in The Origins of the Telescope (2010) we know that Zacharias Jansen was not a potential inventor of the telescope.
Accounts disagree on whether Lippershey’s original instrument was made with a convex and a concave lens providing an upright image, or two concave [sic] lenses providing an inverted image, but they agree that the instrument provided three-times magnification of distant objects.
This is no disagreement whatsoever; Lipperhey’s telescope had one convex (objective) and one concave (eyepiece) lens. One couldn’t construct a telescope with two concave lenses, which is obviously a fatal, given the context, typo for two convex lenses.
Word reached Italy in 1609 and Galileo created his own modified version. By the end of the year, he had built a telescope that could magnify 20 times. He was the first to turn it skyward for a concerted series of astronomical observations. With his new instrument, Galileo discovered Jupiter’s four largest moons, observed a supernova, verified the phases of Venus, and observed sunspots.
The only difference between Lipperhey’s telescope and Galileo’s was the focal length of the lenses; I’m not really sure that qualifies as modified. Galileo was not the first to turn it skywards for a concerted series of astronomical observations; this honour definitely goes to Thomas Harriot and it is possible that Simon Marius also preceded Galileo in telescopic astronomical observations. Galileo did not observe a supernova with his telescope. The last supernova observable in Europe was in 1604 that is four years before the telescope was invented.
What makes all these errors even more embarrassing is that if the author had actually read the literature that she lists at the end of her article then she could have written a factually accurate article.
Inspired by this years 250th anniversary of the Mason-Dixon line I took down my tsundoku*** copy of Edwin Danson’s Drawing the Line: How Mason and Dixon Surveyed the Most Famous Border in America from the geodesy and surveying section of my humble home library.
From the beginning, whilst reading I was irritated by minor historical errors and an aggressive promotion of the Dava Sobel warped version of the longitude story. However my irritation boiled over when I read the following:
In 1753, Johann Tobias Mayer (1723–1762), the Swiss astronomer and professor of geography at Göttingen published a table of lunar distances…
The man who made the lunars method of determining longitude viable was Tobias Mayer; Johann Tobias Mayer (1752–1830) was his son, who after studying in Göttingen became professor of mathematics in Altdorf in 1780. Tobias Mayer was born in Marbach and grew up in Esslingen, which makes him thoroughly German and not Swiss. Lastly he was professor of economics in Göttingen not geography. I those days there was a department of economics and mathematics at the university and it was the latter, which Mayer actually taught.
Slightly earlier in the text a statement that almost set me off was:
The clarity of Auzout lenses, mirrors and telescopes enabled Huygens to improve the observing accuracy of Jovian eclipses and to discover the rings of Saturn.
The observing accuracy of Jovian eclipses was due to Giovanni Domenico Cassini, here falsely called Gian Domenico, and not to Huygens. Huygens did not use the lenses and telescopes of Adrian Auzout but famously constructed his own together with his older brother Constantijn. Huygens also did not discover the rings of Saturn but correctly hypothesised their existence by analysing all of the earlier records of the observations of this particular phenomenon.
Earlier than this Danson, a surveyor, makes the standard error of attributing the invention of triangulation to Willebrord Snel van Royen instead of Gemma Frisius. All of this would normally have had this mild mannered historian of science hurling this volume at the wall but on this occasion I persevered.
As I said above Danson aggressively promotes Sobel’s warped version of the longitude story including the myth that the Board of Longitude discriminated in favour of Maskelyne against Harrison because the latter was working class, whereas Maskelyne was a gentleman scholar. This is patent rubbish, as almost all of the eighteenth-century British instrument makers, regarded as the best in the world, were working class and were highly respected and honoured by the scientific community. Danson, when introducing Maskelyne, sets up this supposed class rivalry as follows:
With the start of the Michaelmas term , Maskelyne returned to his college [Trinity] to take Holly Orders, a prerequisite for a Cambridge fellowship in the eighteenth century. In the tower above Trinity College, the inventor of the chronometer, John Harrison, was busy installing one of his famous turret clocks, oblivious of Maskelyne, his future adversary, strolling around the quad bellow.
I must admit that I was mildly excited when I read that, what a fascinating historical coincidence, if it’s true, but is it true? I had never come across this claim before, maybe it’s in Sobel’s book, but I don’t remember it, I read it many years ago. Stimulated by the claim I did what I always do in such circumstances, I went looking for evidence.
The Trinity College Tower Clock is quite famous so I was reasonably certain that I could dig up something on its history fairly easily and I was right. On the Trinity website we have a webpage titled, The College Clock. This tells us that the clock was constructed by one Richard Holdfield in 1610. A new clock and dial-plate was put in place under the Mastership of Richard Bentley in 1726-27. No clock maker in named but Harrison was still in Yorkshire at the time and it’s also not 1755. The clock was renewed once more in 1910 long after Harrison was deceased. Had Danson completely invented this episode, he had proved to be a bad historian, but falsifying a whole story? I dug deeper.
Tower or turret clocks need regular maintenance and repair and on the Cambridge University Digital Library website we find a drawing of a turret clock escapement, which was designed by John Harrison for a turret clock at Trinity College, Cambridge, dated 1755. Not a whole clock but at least part of one. Danson’s honour as an author is restored or is it?
The entry goes on:
Though designed by Harrison, the escapement was actually made by another clockmaker, William Smith, something which was far from unusual in the extensive sub-contracting system which was fundamental to the production of time-keeping devices in the eighteenth century.
Made and one can reasonably assume installed by William Smith, so no close encounter of Maskelyne and Harrison in Trinity College in 1755.
Later in the text we are in America surveying with Mason and Dixon when Danson informs us that:
For their mathematical and trigonometric calculations, the surveyors used seven-figure logarithmic tables. John Napier invented logarithms, a tabular method for multiplication and division, in 1614; in 1624 his colleague, Henry Briggs, published a set of natural logarithms (log tables), and later developed tables of trigonometrical logarithmic functions (trig tables). The slide rule had also been invented and perfected between 1654 and 1683 by Seth Partridge and Henry Coggeswall.
Where to begin? Napier did invent logarithms in 1614 and published the first log tables, which are often falsely called natural logarithms (i.e. logarithms base e), although they are closely related to natural logarithms. In 1624 Henry Briggs published the first tables of common or base 10 logarithms and not natural logarithms. John Speidell had published the first table of what were effectively naturel logarithms based on Napier’s work in 1619. The first description of natural logarithms was by Nicholas Mercator in 1668. Tables of trigonometrical logarithmic functions are not trig tables. Surprisingly, trig tables are tables of trigonometrical functions. The slide rule was invented by William Oughtred in 1630. Seth Partridge developed the moving slide/fixed stock principle in 1657. Henry Coggeshall developed the so-called carpenter’s slide rule for measuring the dimensions of timber in 1677.
All of this leads me to ask in John Wiley & Sons Inc., a large and successful academic publishing company, the publishers of Danson’s tome, have actually heard of fact checking or if they just don’t care. The mistakes that I have picked up on here are all fairly elementary history of science errors and make me as a reader of the book wonder how much of the other information in the book is trust worthy. If I was doing anything formal on Mason and Dixon I would be very wary of quoting anything from Danson’s book before checking it thoroughly against other sources.
The sloppiness of both Wilson’s article on the telescope and Danson’s book on the Mason-Dixon line make me angry because with a small modicum of effort on the part of the respective authors the mistakes they have made could easily have been avoided.