[72] Taken from a paper on the subject, by Mr. Peter Gray, in the Mechanics’ Magazine.

[73] Taken from the late Mr. Peter Nicholson’s Essay on Involution and Evolution.

[74] Taken from the late Mr. Peter Nicholson’s Essay on Involution and Evolution.

[75] Taken from the late Mr. Peter Nicholson’s Essay on Involution and Evolution.

[76] Taken from the late Mr. Peter Nicholson’s Essay on Involution and Evolution.

[77] A four-sided figure, which has two sides parallel, and two sides not parallel.

[78] The right angle is divided into 90 equal parts called degrees, each degree into 60 equal parts called minutes, and each minute into 60 equal parts called seconds. Thus, 2° 15′ 40″ means 2 degrees, 15 minutes, and 40 seconds.

Transcriber’s Notes:


The cover image was created by the transcriber, and is in the public domain.