Lectures on Select Subjects in Mechanics, Pneumatics, Hydrostatics, and Optics, Plate XIX
Description:
“Plate XIX” features eight figures to accompany the text entitled “Of Optics.” Figure 1 illustrates the manner in which light travels through a multiplying glass to the eye. Figure 2 diagrams the optical physics of the portable box camera obscura with a mirror to right the inverted image. Figure 3 illustrates the physics of the common looking glass. Figure 4 explains the optical illusion of reduced proportion in a looking glass. Figure 5 illustrates the separation of light into the color spectrum through a glass prism. Figure 6 is a diagram of the color spectrum of light on a wheel. Figures 7 and 8 are small geometric diagrams mapping the movement of light rays in the illusion of an arched rainbow.
Copyright:
Copyright 2009, Department of Special Collections, Memorial Library, University of Wisconsin-Madison, Madison, WI
Location:
Primary Works:
Lectures on Select Subjects in Mechanics, Pneumatics, Hydrostatics, and Optics
Accession Number:
Thordarson T 1061
Height (in centimeters):
17
Width (in centimeters):
18
Marks Description
Inscr. top left “Plate XIX”; lower left “J. Ferguson, delin.”; and lower right, “J. Mynde Sc.”Printing Context
“Plate XIX” of twenty-three folded plates appears in Lectures on Select Subjects, first edition. This version of Lectures on Select Subjects is bound with Astronomy Explained upon Sir Isaac Newton’s Principles and Made Easy for those who have not Studied Mathematics, Third Edition (1764), and A Supplement to Mr. Ferguson’s Book of Lectures on Select Subjects in Mechanics, Pneumatics, Hydrostatics, and Optics, with the Use of Globes, The Art of Dialing (1767).Associated Events
James Ferguson (1710–1776) was elected a fellow of the Royal Society of London in 1763. On April 1, 1764, Ferguson observed the eclipse of the sun from Liverpool, England, about which he wrote a paper for the Royal Society entitled, “Observations on the eclipse of the sun” that same year (P. Rothman, “Ferguson, James” Oxford DNB).Associated Places
The Royal Society of London.Associated Texts
Astronomy Explained published in 1756 (1st ed.) and reprinted in 1757 (2nd ed.), 1764 (3rd ed.), 1770 (4th ed.), 1772 (5th ed.), 1778 (6th ed.), 1785 (7th ed.), 1790 (8th ed.), 1794 (9th ed.), 1799 (10th ed.), (P. Rothman, “Ferguson, James”).Subject
The camera obscura portrayed here is an excellent example of Ferguson’s interest in the physical properties of the scientific problem at hand. Instead of illustrating a portable box camera obscura with a cut-away side view to reveal the inner mechanisms of lens and mirror, Ferguson, the delineator of the plate, does away with the outer form of the device completely and diagrams instead the physical pathway of an image through the camera obscura.Theme
Optics, light, lenses, camera obscura, looking glass, prism, color spectrumSignificance
The text in Lectures on Select Subjects was drawn from James Ferguson’s extensive public lectures on a variety of scientific topics. A self-taught scientist and a Fellow of the Royal Society, Ferguson sought to elucidate both his texts and his lectures for easy comprehension by his public. Ferguson said, “I had a view … to avoid all superfluity, and to render everything as plain and intelligible as I thought the subject would admit of” (qtd. in P. Rothman, “Ferguson, James" Oxford DNB). His sentiments align with concurrent popular interests in science as a rational and edifying recreation, exemplified in texts by M. Guyot, William Hooper, and Jacques Ozanam, and by the serial public lectures given by Ferguson, Joseph Priestly, and other natural philosophers. According to Jessica Riskin, these lecturers’ “efforts to amuse were dramatically successful. Fashionable people thronged to see nature’s ways laid bare” in the late eighteenth century (J. Riskin, “Amusing Physics” 43). The intention of this type of public lecture was to be both didactic and amusing, rather than tediously difficult or boring; further, “an insistence on simply seeing permeated the amusing physics curriculum,” an impetus which parallels the copious illustration accompanying this type of text in the eighteenth and nineteenth centuries (J. Riskin, “Amusing Physics” 45). Ferguson, however, did not shy away from the mathematical complexities of these topics in either his lectures or his texts, nor did he necessarily suggest experiments for the amateur scientist to perform at home. Rather, an understanding of the figures on “Plate XIX” and the associated text from Lectures on Select Subjects requires a high level of scientific and visual literacy.Function
A textbook on the subject of optics.Bibliography
Crary, Jonathan. Techniques of the Observer: On Vision and Modernity in the Nineteenth Century. Cambridge, MA: MIT Press, 1990.Long Title
James Ferguson, Lectures on Select Subjects, Plate XIX: Optical physics and instruments, copper plate engraving, 16.8 x 17.5 cm, inscr. top left “Plate XIX,” lower left “J. Ferguson, delin.,” and lower right, “J. Mynde Sc.,” Thordarson Collection, UW Department of Special Collections.Featured in Exhibit:
Engraver:
Delineator:
Image Date:
1764
