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JF Ptak Science Books Post 1977

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It seems to me that in the history of astrology–or at least for what seems to be most of it, at least through the late antiquarian publishing aspect of it–that comets and meteors were basically not utilized. Perhaps it was because in that world these entites didn't really effect anything–perhaps they were simply mysterious, spurious, and incongruent, and not a subject for installation in the astrological night sky. Comets (from the Greek, kometes, "long-haired") and meteors (Greek again, from meteoran, a "thing in the air") and bolides (exploding meteors, from the Greek bolis, or "missile"), holosiderites, siderolites, aerolites uranolites, and so on, have a long and complex story in the history of astronomy, at least in some ways; perhaps the most influential thinker on comets held thinking at bay and did so for two milennia: Aristotle's Meteorology made the case that comets were not a planet or associated with planets or even necessarily part of the heavens–rather they were a phenomena of the atmosphere. So perhaps their use as astronomical/astrological objects was limited by their very Aristotlean obviousness of being near-Earth objects.

The Comet of 1066 (later named Halleys' Comet), as depicted in the Bayeux Tapestry (completed in the 1080's)

Comets bayeux

The fear aspect of comets–the Comet of 1528–was depicted in Ambrose Pares Livres de Chirurgie (1597), and shows what part of the concern was (the coming demise of nations, the death of rules) with the appearance of decapitated heads and a large sword and raining daggers:

Comet pare

Comets 1560
[Nicolas Le Rouge, Le Grand Kalendrier et Compost des Bergieres, published in 1496 in Troyes.

The night sky is a mnemonic device, a place to store memory and a holder of the alphabet of myths and beliefs of all, a culture written large across the sky. Meteors and comets were not predictable, and could add nothing insofar as a consistent bit of storytelling was concerned, though they certainly created their own stories in each observed appearance; they could also add punctuation and exclamation to whatever constellation they appeared in. For example if one appeared in a juncture with Jupiter, a major event for royalty would possibly be foretold. But as a permanent element to the visualization of the night sky, they had little power even though they seemed to be displays of fantastic energy and power in themselves.

Comets 3562
[For some reason the celestial court, divided by sunlight and flanked by two other sources of light, have ofund it expedient to issue comets from the mouths of Heaven Canon. I'm not sure what's going on in the forground with the fellow working his spade next to the triangular blankness. the man to his right seems to have been overtaken in fear (as have the group of people visible to the left over the shoveler's shoulder).]

Comets 4563

[Halley's comet appears again on the title page of this work by the Hungarian George Henischius, a professor of rhetoric, mathematics and medicine at Augsberg.]

JF Ptak Science Books Post 1963

Sometime we see a Cloud that's dragonish,
A Vapour sometime like a Bear, or Lion,
A tower'd citadel, a pendant Rock,
A forked Mountain, or Promontory,
With Trees upon't, that nod unto the World
And mock our Eyes with Air.– Anthony and Cleopatra (Act IV Scene II) from the title page of Cozens' A New Method…, 1785

This blog maintains a longish thread on the History of Dots, but no where in there yet is any appreciation or discussion of the blot (the "blot" being "the unhappy and rejected love of the Dot" not according to Ambrose Bierce).

Cloud-writing is difficult work, mostly because it involves making the invisible visible in an imaginary landscape. This is I think exactly what Alexander Cozens (1717-1786) had in mind when he wrote about using ink blots for inspiration in preparing a landscape, writing about it in his A New Method of assisting the
Invention in Drawing Original Compositions of
. In 1785. He had the idea in mind and was using it in lessons for decades before that, but the work only found its way into print at the end of the century, a year before his death–and more than a century before such thoughts began to enter the early archaeology of the social meme. In a way he wrote about implementing a sort of simple calculus of discovery, of seeing the impression of possibilities in, well, anything, but particularly in the memory and sensation of forms.

These weren't literally what we would think of today as ink blots–they were suggestive forms that sort of looked like blots from which more determined and refined images could be made. He suggested that landscapes be generated as instinctively as possible, with blots being used to arouse memory and curiosity and to be incorporated into or suggestive of natural forms in constructing the landscape. [Although the word "blot" reaches back into the 14th century according to the OED, the version that Cozens had in mind I think was the verb "blot", which appears around 1440, and which means "to spot or stain with ink or other discolouring liquid or matter; to blur" (emphasis mine). It seems to me that the blot art that Cozens had in mind was both a blurring and a refining method, something that could release the artist and allow the mind to roam freely around the blot's inspiration and the artist's landscape memory. as Simon Schama says about the blot in Landscape and Memory, "there blots were deliberately random impressions meant to express, rather than to slavishly outline, the natural heaping of rock forms. The impulsiveness and spontaneity of their production served to reinforce the new idea...that mountains were dynamic, even turbulent things..." (page 461).]

Cozens was working on imagination and discovery, a way to make an improvisation in art, a riff on whatever the ink blot might suggest to the viewer. On page seven of his pamphlet he describes The Blot:

‘A true blot is an assemblage of dark shapes or masses made
with ink upon a piece of paper, and likewise of light ones produced by
the paper being left blank. All the shapes are rude and unmeaning, as
they are formed with the swiftest hand. But at the same time there
appears a general disposition of these masses, producing one
comprehensive form, which may be conceived and purposedly intended
before the blot is begun. This general form will exhibit some kind of
subject, and this is all that should be done designedly’ (p.7, from The Tate description),

  • Cozens blot[An example of Cozens' work with the blot, source: the Tate]

In a way it Cozens reminds me of Leonardo's cracks and shadows:

"…if you look upon an old wall covered with dirt, or the odd
appearance of some streaked stones, you may discover several things like
landscapes, battles, clouds, uncommon attitudes, humerous faces,
draperies, &c. Out of this confused mass of objects, the mind will
be furnished with abundance of designs and subjects perfectly new".–Leonardo Treatise on Painting (in the English translation published in 1721), pp 5-6

Another example from the Metropolitan Museum of Art of Cozens' "A Blot-Lake with Boat, Surrounded by Trees":

Cozens blot art lake
Cozens worked for insight, for "the art of seeing properly", for surprise, the discovery of forms. IT was an extraordinary work, especially given its time, ten and more decades and more away from the work of Redon and ernst and the rest of the suggestive painters, and even seven decades out from Courbet. It was slightly closer in time to the quizzical work of Justinus Kerner, whose Kleksographien of 1890 used ink blots in a parlor-game fashion for his readers to fashion stories and narratives with. (A full text with illustrations of the 1890 edition of the work is found here, in the digital collections of the University of Heidelberg).

An example of Kerner's work:

Kerner i,age

And well in advance of Hermann Rorschach's 1921 book Psychodiagnostik, which employed the use of ink blots to help him diagnose schizophrenia, the predictive and diagnostic aspect of the idea coming in 1939, not as a result of Rorschach's doing).

What these blots might all have in common was their pre-modern earliness. their anticipation of something that would become a standard framework in the decades–or centuries–to come.

JF Ptak Science Books Quick Post Part of a series on The History of Dots

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Colbert de Lostelneau's (French Marshall and Commander of the French Royal Guards) Le
mareschal de bataille..
.1and printed by Estienne Mignon
in Paris inthe year 1647, is one of the earliest books to be printed in
colros. This rare book, which was a superior cummulative work on
tactics and strategy and military thought (and which in parts leaned
very heavily on earlier and sometimes unattributed books), employed the
new venue of color printing to highlight its musketeers/pikemen/cavalry
symbols in three shapes and in three colors for easier understanding of
the movement of three different aspects of an army. It is said that in
this way the military theory was made more adaptable and practicable.

In the history of dots, though, these color-printed varieties are significant as being among the first of their kind.

Color dots detail
And the full image (both of which are located at Gallica–website for the Bibliotheque Nationale de France, here):

Color printing dots lostelneau

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JF Ptak Science Books Post 1932

"That those spots and brighter parts which by
our sight might be distinguished in the Moon, do show the difference between
the Sea and Land of that other World… The spots represent the Sea, and
the brighter parts Land… That there are high mountains, deep valleys,
and spacious plains in the body of the Moon… That there is an atmosphere,
or an orb of gross vaporous air, immediately encompassing the body of
the Moon… That it is probable there may be inhabitants in this other
World, but of what kind they are is uncertain…"–
Discovery of a New
World in the Moone
(1638). by astronomer John Wilkins

Reading about the rover Curiosity taking bites of the Martian surface to analyze brought to mind an early and elegant piece of reasoning which put to rest the claims of life on the Moon. Belief in Lunar life is ancient, stretching back (for example) to Pythagoras, Plutarch and Lucian (who wrote perhaps the earliest piece on flying off to another non-celestial sphere). In more recent times bigger scientific names get thrown into that selenite melting pot: Carl Friedrich Gauss was a believer int eh possibilities of life there, as were the astronomers Helevius, Bode and (later on) Olbers, Littrow and Gruithausen. (Franz von Paula Gruithuisen [1774-1852] published his findings of urban structures in the very rough terrain above the Schroeter crater; his Wallwerk was quickly discredited though by astronomers with more powerful telescopes.)

Schroeter crater
[The seat of the problem for Gruithuisen--the complex structures at left thought by high in observation a low-powered refracting telescope to be streets and buildings. Source: NASA/JPL/University of Arizona, University of Arizona's HiRISE (High Resolution Imaging Science Experiment).]

In addition to the improvements in telescope resolving power–which provided better/more accurate maps of the lunar surface, particularly in the 1830's by Beer/Maedler and Lohmann–there was a major piece of thinking by Friedrich Bessel (1784-1846). Bessel was a superb observationalist and contributed vastly to the field with his work on stellar distance and identification, publishing his Fundamenta Astronomiae in 1818 and consequently constructing a star catalog of 63,000 objects. In 1834 he established that given the very sharp occulations that the Moon's diameter was found to be not very much smaller at all in relation to its measure by direct observation, meaning that the starlight was not deviated by atmospheric reaction, because the atmosphere of the Moon such as it was was 1/2000th of the density of that on Earth. Therefore: no perceptible atmosphere, no respiration, no life as it was understood to be "living".

Very pretty.

It is odd that given that work and the very barren maps being produced in the 1830's and the higher-powered telescopes that showed masses of scarred surface that there was a flurry of pro-Lunar-life stuff to hit the popular newsstands just a few years later. A famous (and first?) case of this was with Edgar A. Poe's "The Unparalled Adventures of One Hans Pfall" which appeared in the Southern Literary Messenger in June 1835 and which detailed the story of a debt-ridden Pfall who takes off to the Moon in a hot air balloon for it more debt-free climate, and who then sends back a Selenite messenger on another balloon, and, well, nothing really happens. A much ore effective hoax was perpetrated in the New York Daily Sun for six days in August 1835 in a story attributed to the great astronomer William Herschel about find vast and complicated life on the Moon. (In real life Herschel was a believer but I think never published on it.)

It is odd that such a fair amount of activity–something which was also the modern beginnings of ET-based storytelling of fear and hope–would begin a year after Besell's thinking. And in a reutn-to-home0again, the crater nearby the Wallwerk of Gruithuisen (who also claimed that the whitish polar icecaps of Venus were caused by fire ceremonies by practicing Venetians), named Schroeter, was done so in the honor of the astronomer Johann Schroeter (1745-1816), for whom Besell worked as an assistant. ( Surveyor 2 landed about 100km from the Schroeter crater, as well.)

JF Ptak Science Books Post 1791 [Part of the History of Dots series.]

Def. 1.1. A point is that which has no part.
Def. 1.2. A line is a breadthless length.
Def. 1.3. The extremities of lines are points

Euclid, The Elements

Please see the associated post on the History of the West and the History of Lines: Telegraphs, Railraods, Treaties, and Barbed Wire.

I really don't mean to tangle this post up in what might be one of the most profoundly significant books ever written, mainly because the I'm talking about "dots" and not "points", though several points do come into play in the story.

The dots come into the story with the finishing of the great Overland Route, the Transcontinental Railroad, which was built between 18631 and 1869, and which via massive construction tied together various lines to make the fist continuous connections by rail between the American Atlantic and Pacific coasts. The construction for the vast missing connecting chunks were undertaken by the Central Pacific Railroad of California and the Union Pacific Railroad, building (respectively) their ends extending from Oakland (CA) to Council Bluffs (IA). (A map of the railroad line can be seen below in a clickable whole and then again in the "continued reading" part of the post in more detailed sections. Interestingly this map shows both a plan and profile of the line, and when you take a closer look at the bottom part of the map it is easy then to see why the Central Pacific had so many delays getting through the Sierra Nevada.)

The building of the railroad line was notoriously difficult, undertaken by companies desperate to build their ends fast and not using the best materials or doing the best work (with millions needing to be spent on repair of the Central Pacific effort as soon as the line was completed), or treating the largely immigrant workforce (mainly Chinese and Irish) fairly. But the job did get done and it got done relatively quickly, considering too that the first primitive locomotives didn't appear in the U.S. until 1831–it didn't take long at all to produce thousands of mile of line as well as the sophisticated machinery to run on them. The great engineer Oliver Evans waged a little war on the future by allowing himself to see the following:

"The time will come when people will travel in stages moved by steam engines from one city to another, almost as fast as birds can fly, 15 or 20 miles an hour…. A carriage will start from Washington in the morning, the passengers will breakfast at Baltimore, dine at Philadelphia, and sup in New York the same day…. Engines will drive boats 10 or 12 miles an hour, and there will be hundreds of steamers running on the Mississippi, as predicted years ago." –Oliver Evans, 1800 [Evans built the first stationary steam engine in 1800, and then in 1804 built the first steam engine powered boat.]

He wasn't talking about railroads per se, as the steam locomotive hadn't been invented yet. But 30 years later or so there was the first appearance of these machines, and then another thirty years after that they were running across the United States, which was a remarkable turnaround in the economy of transportation.

The very end of this story though is told in dots. When the Central Pacific and the Union Pacific met in the lonely Promontory Summit, Utah, there was an on-site celebration where the two lines were famously tied together using a golden spike. (Actually there were two gold, one silver one blended gold/silver, and one plain spike used int he ceremony.) The news of the event was carried out to the rest of the country via another new and remarkable medium, the transcontinental telegraph, which had been completed in October 1861 and which allowed nearly simultaneous communication between the two American coasts, with this innovation also taking place about 25 years after the general invention of the telegraph.)

It is interesting to note that it was during the Lincoln administration–in the earliest part of Lincoln's presidency–that these two great unifying elements were established. The railroad was started in the first year of the Civil War, and the telegraph finished just months into the conflict. It is ironic that the first communication going west-to-east by Stephen J. Field (on 24 October 1861) to President Lincoln spoke of the medium's great power in uniting the country, if only East and West: "will be the means of strengthening the attachment which binds both the East and the West to the Union". Which may or may not have been true–communications wouldn't necessarily unite, as the country was already deeply at war with itself North and South, and there were already ample telegraphs enough existing between the two that did not manage to keep the country firmly within itself.

Back to Promontory–the proceedings of the celebration were "broadcast" by telegraph, the event being very heavily listened-to news. There were speeches of course and then toward the end there was a sermon followed by a long entreaty to the almighty. That finished, the Central Pacific top man, Leland Stanford, was to drive home the final golden spike uniting the lines. When the spike was driven and finished, the news would be related by the telegraph as so:

"Dot. Dot. Dot."

Three dots would signal the end of the work, and the completion of the railroad. Stanford reportedly missed on his first swing with his silver hammer, but the news was sent out anyway, saying the work was done. The signifier relating the connection of thousands of miles of railway track being three simple dots.

Hart stereoview #355, detail. Courtesy National Park Service.
Hart stereoview #355, detail, "The Last Rail – The Invocation. Fixing the Wire, May 10, 1869."
Courtesy National Park Service. [Source for image, here.]


1. Abraham Lincoln signed the Pacific Railway Act in 1862 which set the stage for the building of the Transcontinental.

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JF Ptak Science Books Post 1787 History of Dots Series

Ring the bells that still can ring
Forget your perfect offering
There is a crack, a crack in everything
That’s how the light gets in.
–Leonard Cohen

I meant this title toAaa-light fiz gears det159 this post quite literally—among the earliest mostly-accurate estimation for the speed of light (“c”) was made by Fizeau in 1849, and he not-literally made an image of what the speed of light “looked like”, the last dot in a crack that let the light in. It followed several hundred years of thinking on the speed of light including experiments employing lanterns (Galileo), the Moons of Jupiter (Ole Roemer), rain and starlight (James Bradley), and which in turn followed thought experiments by Empedocles, Aristotle and Descartes, who reckoned the speed of light to be instantaneous. The Parisian physicist Armand Hippolyte Louis Fizeau (September 23, 1819 – September 18, 1896) acted on a beautiful idea and constructed an elegant apparatus (again using lanterns) to make the first modern estimate of c. And, basically, as soon as he was finished and published the results in the Comptes Rendus in 1849, Leon Foucault—with whom Fizeau worked on many occasions—improved the apparatus and made an even closer approximation.

Aaa-light fiz gears158

The way the apparatus worked was simple and powerful: Fizeau observed a light through an optical apparatus with a rotating toothed gear between observer and the entry of the light source; a mirror that was more than 5 miles away reflected that beam back through those same geared teeth of the disk. The disk could be made to rotate at specific speeds, the object being to calibrate the disk to prevent the light from going through the teeth of the gear to the mirror and then back again through the same gap. The point at which the dot o flight disappeared could be easily calculated and the speed of light extrapolated from there–which Fizeau estimated to be 313,300 Km/s or 194,410 miles/second. (In 1850 Foucault replaced the toothed gear with a mirror and produced a more accurate estimate of 185,093 miles/second, which in fact turns out to be very close to c.

Aaa-light fiz apparatus160

Historical Estimates of c in Km/s

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JF Ptak Science Books Quick Post Part of the History of Dots series

Dots--game France
There are many board games in the history of boards games that utilize dots similar to this game, but this one seems mightily different given the dots' odd arrangement, and seeming disambiguation, and the means to the ends of the "race". It is an unusual arrangement, or so it seems to me, given the amount of blank space and the connected dis-connectedness of the routes. The game looks to me more of a capturing of empty space than a competition of getting from Paris to Bruges in the shortest amount of time…though not in a space-capturing sense of Go–just in defining the empty space.

JF Ptak Science Books Post 1715 [Part of the History of Dots series.]

I wanted to land this post (the title of which is nearly as long as the article) on this little island in a wide sea of similar islands in the complicated 18th century history of embryology. Where we came from and how living things developed really wasn't very clear at this time, and really wouldn't be until Karl Ernst von Baer discovered the human ovum in 1827.1

HomunuclusThe issue of the ovaries as ovens–of homunuclus and palingenesis and epigenesis, the imaginary male-dominant anatomy of reproduction–was pretty much somewhat solved by the beginning of the 19th century. Or at least the homunculus, the tiny but perfectly formed miniature human traveling along in sperm, was. This character is pictured here, riding in the squinty-eyed imagination of researcher Nicholas Hartsoeker2, who desperately wanted to see the thing, I think, and which found itself published in his book Essai Dioptrique in 1695. Spermatozoa was discovered earlier by the great Leeuwenhoek (1632-1723) and which was finally confirmed in its fertility hypothesis by Lazzano Spallanzani, who also happened to be an ovist, thinking that each egg contained a pre-formed embryo).

The woman as a simple baker of a gift of preformed life was a medical belief that helped perpetuate the supposed inferiority of women, and that the woman’s part in the procreative process was a simple oven. It was a difficult image/belief to resist, persisting well into the 19th century. But there was another side of this debate as well, and that was that woman didn't need the male sperm to proceed with the process of conception, with some scientists believing that coition had nothing whatsoever to do with the process. And so there were battle lines drawn in the primordial embryological sand of the 18th century, each demanding a sex-dominant role in procreation.

And if sperm contained a perfect, pre-formed human being, waiting to be planted in the oven of woman, what happens to all of those-pre-forms in the sperm that went "unused"? I imagine that if you were an 18th century pre-formationist that this would be a tricky and very uncomfortable question. If you could put on special sperm-specs that would allow you to see "ejected" and "unused" sperm in the same sort of ways in which we can see non-visible light, that, well, you might want to watch your step and avoid smashing a fully-formed human being that had the potential of living for weeks on its own with the benefit of anything else at all. I have to admit that even for me this makes the picture of this Earth not very savory. The author of "A Brief History of Sperm" at points out that at least one English country doctor, James Cooke, thought that this ejecta "might not die", at all,

"… but ‘live a latent life, in an insensible or dormant state, like Swallows in Winter, lying quite still like a stopped watch when let down, till [they] are received afresh into some other male Body of the proper kind’."–from, in its "A Brief History of Sperm".

It sounds a little like embryologico-guerrilla warfare.

In the middle of the sides drawing themselves up for battle, choosing male- or female-dominant mechanics of procreation, or a combination of both, were the supra-ovists, who claimed that in this mess that every human who would ever be born on Earth was already present in the ovum of Eve. There were some who tried to calculate the figure of how many people that ovum contained, but like the creation timeline of Bishop Wilberforce, the numbers were open to severe self-definign interpretations.

It is interesting to note these debates, though, because they weren't really finally settled until just three generations ago. (Or four if you're much younger than I.)


1. von Baer published his discovery in his Epistola de Ovo Mammalium et Hominis Genesi (Leipzig, 1827), followed by his two-part Ueber die Entwickelungsgeschichte der Thiere in 1828 and 1837 on the history and evolution of animals. The original paper did not catch on, immediately, and took some years to be established. There was actually a paid competition going on in Europe at this time for the purpose of finding the ovum, and although aware of the award and thinking he had found the "prize", von Baer was not well-doisposed to the idea of the "race", and so really didn't participate. Jean-Louis Prevost (1790-1850) and Jean-Baptiste A. Dumas (1800-1884) also came to the conclusion that the "animacules" in the semen were responsible for fertilization. The deal wouldn't be solidified until Oskar Hertwig actually observed the fusion of the male and female material in the ovum of a starfish in 1876.

2. Hartsoeker ("heart seeker") (1665-1725) was a microscopist of high order in addition to being a physicist and a medical doctor, never actually saw this thing in his investigations–he iterated that the little person must be there. But he never did say that he observed it.

JF Ptak Science Books Post 1690 [Part of the History of Dots series: Weighing Earth's Biggest Dot--Itself.]

Archimedes said that given certain conditions and equipment that he could lift the Earth with a lever; he did not, however, have the necessaries to actually determine how much the whole thing "weighed", and would have to wait for 20 centuries in the work of Henry Cavendish to have an answer. (Archimedes was a very busy man with an enormous list of contributions, and was perhaps the greatest physicist and mathematician of his age in the third century BCE, but he did not invent the lever–he did however provide the mathematical understanding and formalization of how the thing worked in his "On the Equilibrium of Plane Figures".)

In this experiment, "Experiments to determine the Density of the Earth", the results of which appeared in the Philosophical Transactions in 17981, the great and somewhat mysterious (and odd) Henry Cavendish determined to, of all things, weigh the Earth. (Well, really it was measuring the force of gravity and finding the gravitation constant G, which Cavendish referred to as the specific weight of the Earth.) Now there are certain remarkable things to be achieved in the 18th century (like for example the discovery of oxygen by Scheele/Priestly), and of course the idea of measuring the weight of the Earth was a high intellectual achievement. Cavendish set off to measure the force of attraction between large and small lead balls using as a basis for research parts of his dead friend John Michell's designs for a torsion balance (which he had created in 1783), and using of course Newton's laws showing that the force of gravity between two objects depends on their masses as well as the distance between them. Michell had thought of the experiment years before but died before he could present; Cavendish carried on and up, and out. Mind he wasn't the first on the spot (Coloumb was there too slightly before Michell), or the first with the idea–he was the first to complete it, though, taking the difference in the measures on the very sensitive balance from a distance using a telescope so as to not disturb the readings. As a matter of fact this was the only method employed to conduct this experiment for nearly another hundred years, the results being confirmed by a number of scientists2 over the coming decades. It was a lovely idea, and a fantastic piece of work.

In his paper in the Philosophical Transactions, Cavendish described Michell and the instrumentation int he opening two paragraphs:

The instrument:

File:Cavendish Experiment.png

This is the test apparatus that Cavendish constructed following the original Michell plans–it was a big, solid instrument, as that horizontal piece suspended fro the rod ( K) is six feet long, and those two spheres ( W) attached to its ends are 350-pounds apiece. The smaller sphere is located in the box to the side of the large sphere, as so:


“Henry Cavendish had fitful habits of publication that did not at all reveal the universal scope of his natural philosophy. He wrote no books and fewer than twenty articles in a career of nearly fifty years. Only one major paper was theoretical, a study of electricity in 1771; the remainder of his major papers were carefully delimited experimental inquiries, the most important of which were those on pneumatic chemistry in 1766 and 1783–1788, on freezing temperatures in 1783–1788, and on the density of the earth in 1798.” (D.S.B. III:155).



1. A copy of the first German edition of this work is available at our blog's bookstore: "Versuche über die Dichtigkeit der Erde zu Bestimmen." Halle, Rengerschen Buchhandlung, 1799, and published in Annalen der Physik, herausgegeben von Ludwig Wilhelm Gilbert, band. 2, erstes stück. 120pp in this section, 488pp overall in in the entire volume, with 9 plates. Cavendish's paper occupies pp 1-62, with two plates (the torsion balance of Michell shown on the plates).

The entire Cavendish paper can be found here: Cavendish, Henry (1798). "Experiments to Determine the Density of the Earth". In MacKenzie, A. S.. Scientific Memoirs Vol.9: The Laws of Gravitation. American Book Co.. 1900. pp. 59–105 Online copy of Cavendish's 1798 paper, and other early measurements of gravitational constant.

2. The experiment was in fact repeated numerous times, including that by Reich (1838), Baily (1843), Cornu & Baille (1878), among others, and it wasn't until 1895–the year of Roentgen's epochal discovery–that Cavenidsh's accuracy was exceeded by the work of C.V. Boys.

JF Ptak Science Books Post 1651


I don't often see covers of pamphlets featuring hundreds–or thousands–of people as a part of the design. In my continuing role as finder and re-finder of things found I have re-surfaced four of these designs, and I feel I should post them before they're captured in the un-finding process. Again. Back to the design: these are very striking, persuasive images, unavoidable in many ways, completely intriguing, beguiling. People just have to look at these things. Look: I made a little experiment today placing ten very interestingly-designed pamphlets on display, all with compelling and distinct merits, and including one with a big spread of humanity on the cover (the "Life" pamphlet. The very unscientific results is that people were generally first drawn to the complex people image, and stayed longer looking at it–by far–than any other image. Perhaps its the same sort of reaction going on when you watch people walking in front of a mirror or reflective surface, with the vast majority of folks checking themselves out in it. Maybe its just people looking for something familiar. Maybe the faces are simply, strictly more interesting than just points o the page. I'm not sure.

The first image is a one penny Labour Party publication coming from the National Executive Committee of the Labour Party, published in London in 1937; second is Life, the story of the fraternity lamda chi alpha, published around 1935; third, a program for the Liberal Party, published in London in c. 1938; lastly, fourth, a program for some course of semi-statistical study with the John Hancock life insurance company. These beautiful designs were much more interesting than the very casual contents they covered, at least to me.