JF Ptak Science Books Quick Post
Just yesterday I posted on Found-Abstract art (http://longstreet.typepad.com/thesciencebookstore/2018/10/found-art-in-electrical-hardware-1885.html) in a cross section of a conduit of telephone wires from 1885. Just now in research a bit on Tesla I found the following diagram for a classroom demonstration in acoustics (appearing in Nature, 11 February 1892) which could easily be added to a list of unintentional/unrecognized pre-Abstract Art art. If you varied the disks in black and white and motorized the whole thing you could imagine it another decade in the future as a work by Duchamp. As it is, it is an ingenious piece of thinking (the whole article follows):
And one still of many from Mr. Duchamp's "Anemic Cinema", 1926:
For a video of the film: https://youtu.be/dXINTf8kXCc
Also a nice piece on Duchamps optical experiments from Hyperallergic: https://hyperallergic.com/323582/duchamps-spinning-optical-experiments/
From Nature, 11 February, 1892, volume 45:
WAVE MOTION MODEL.
As a teacher of Physics I have always experienced considerable difficulty in giving to elementary students of Sound a clear conception of the motion of the air in organ pipes when sounding. In Weinhold's Physics a method is shown in which a series of sinuous lines drawn on a sheet of paper exhibit this motion when drawn across a narrow slit but the difficulty attending the drawing of these lines has I imagine precluded its general adoption for class purposes.
It struck me that it ought to be possible to draw a series of eccentric circles upon a disk in such a way that when rotated the motion of the intercepted lines as seen through a narrow radial slit should correctly represent this motion. This of course is done for progressive waves by Crova's disk. After spending some thought upon the matter I succeeded in producing such a disk a copy of which I inclose. It has given such satisfaction that I have been advised by several scientific friends to send a description of the method to you for publication for the benefit of teachers and students generally. In the following description I have given the dimensions which I myself employ in describing these disks but they can of course be varied at will. A piece of stout cardboard should be taken about a foot square A line AB 3/4” inch in length should then be drawn near the centre and a circle described about it half of which should then be divided as shown into 12 equal parts. Perpendiculars should then be dropped upon the line AB which is thus divided in harmonical progression in the points I 2 3... 13. With the points 1 2 3 13 12 11 10 9 8 7 successively as centres a series of circles should then be drawn beginning with a radius of 1 inch and increasing it each time by inch. The last circle therefore described with the point 7 as centre has a radius of 4 inch. The two circles described with the point 7 as centre since they represent nodes should be drawn rather thicker than the others to distinguish them. The disk is now complete It should be cut circular in shape and mounted to rotate upon a pin struck through the point 7. If it now be examined by means of anarrow radial slit extending across the marked portion of the disk the short lines intercepted will by their pendulum like motions represent the motion of the air particles in a closed organ pipe giving its first overtone. When the slit is shortened so as to show only the portion of the disk between the two nodal lines the vibration of a rod clamped at both ends will be represented whilst the outer half of the latter length of slit will represent similarly a closed organ pipe giving its fundamental note In this way by restricting the slit to various parts of the disk various vibrating rods of metal and organ pipes can be represented.
The disks thus produced I have had very satisfactorily lithographed for students use Should any of your readers be desirous of obtaining further information I shall be happy to oblige them.
F Cheshire
PS: In the drawing of the disk given the centre has been filled up by broken circles As thus drawn the inner circle may with advantage be blackened over
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