Sheraton, Thomas; Bensley, Thomas; Mathews, James; Bensley, Thomas [Oth.]; Mathews, James [Oth.]; Terry, George [Oth.]; Jordan, Jeremiah Samuel [Oth.]; Wayland, L. [Oth.]: The Cabinet-Maker And Upholsterer's Drawing-Book: In Three Parts (London: Printed For The Author, By T. Bensley; And Sold By J. Mathews ... C. Terry ... J.S. Jordan ... L. Wayland ... And By The Author, 1793)

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manner as at s. Draw the line i g through g and from where
i g cuts the oval, bifedt i g, as at the center r.
Third, On the center j defcribe any circle large enough to
interfedl the circumference of the oval, as at the points c b.
Draw the line c b, and bifedt it, as at u; then draw the long dia-
meter a b through u s, the center ; and, laftly, draw e d parallel
to c b; then will e d be the iliort diameter, a b the long one, and
j the center, as required.
This Problem will be found ufeful in many cafes. For
inftance, when the face of a fire fcreen is a true oval, and it is
required to put the brafs fprings on it after being covered with
paper or filk, &c. in this cafe it will be very uncertain whether
the oval will hang true, if the fprings are only put on by guefs.
To avoid uncertainty, take a fheet of paper and lay on the
face of the fcreen, drawing a pencil round its circumference,
from which proceed to find the diameter as above.
Prob. XIX. Fig. 17.
To find the Center of any fegment or complete circle whofe
circumference is already given.
Operation.-—Let B D A be the fegment whofe center is re-
I 2 * quired.