Engine for grinding hyperbolic glasses
Date
10 June 1669
Creator
Unknown, Artist
Object type
Archive reference number
Manuscript page number
p1a
Material
Dimensions
height (page): 74mm
width (page): 147mm
width (page): 147mm
Subject
Content object
Description
Drawing of Christopher Wren's 'engine' for grinding hyperbolic glasses. This follows on from Wren's publication in Philosophical Transactions of the Royal Society, vol. 4, no. 48 (1669), which shows that a section through the axis of a cylinder was a hyperbolic surface, which could then be applied to create a machine to grind hyperbolic lenses. This drawing, however, is not much more than a geometric diagram with shading, and does not take into account the wheels, cogs and other arrangements necessary to translate this into an actual machine.
Object history
At the meeting of the Royal Society on 10 June 1669, ‘Dr. Christopher Wren explained the model of his engine for grinding hyperbolical glasses, viz. upon what geometrical principle it depends, and how that is to be applied to practice. The president affirmed, that he had considered the principle, it being formerly imparted to him, and had found it mathematically true; and as to its application to use, the success of that depended on experiment. The contrivance was, that in this engine there was a complication of three different motions, whereby three bodies so work upon another, as to produce an hyperbolical figure; any irregularity, by the encountering of one another, being immediately rectified. Dr Wren intimated, that great care must be had in setting the engine, that being somewhat nice, since the three axes must all intersect in a point, and one at the right angles with the other two. It was ordered, that the paper containing the demonstrations of this should be registered, and an engine be made by the care of Mr. Hooke, to try the principle of the matter’ (Birch 2:379).
C. Wren, 'A description of an engine designed for grinding hyperbolical glasses, as it was in a manner promised number 48 (p. 962)', Phil. Trans., vol. 4, no. 53 (1669), pp. 1059-60.
C. Wren, 'A description of an engine designed for grinding hyperbolical glasses, as it was in a manner promised number 48 (p. 962)', Phil. Trans., vol. 4, no. 53 (1669), pp. 1059-60.
Related fellows
Christopher Wren (1632 - 1723, British) , Architect
Associated place