[601]. Loco.-type semi-fixed horizontal engine, with engine on top. When placed on wheels this type constitutes the well-known “Portable.”
[602]. Horizontal semi-fixed boiler, with circular shell and engine on top. (See [No. 72].)
[603]. Horizontal semi-fixed boiler, with underneath fire-box. (See [No. 71].)
Section 34.—ELLIPTICAL MOTION.
[604]. Ellipsograph; by gearing; the bevil wheel A is fixed, the other three revolving with the whole machine on the fixed central standard, the distance A′ should equal the difference between the major and minor axes of the ellipse.
[605]. Performs the same operation in a similar way; A is fixed; B is same diameter as A; and C = 1⁄2 diameter of A and B.
[606]. Common trammel or ellipsograph.
There are other forms of apparatus for drawing ellipses merely (see Knight’s Dictionary of Mechanics). See [Trammel Gear], [Sec. 40].
[607] & [608]. Two forms of ellipsographs or elliptical cranks.