ROBERTSON'S ENGINE.
�551
�which require to be turned through 90, the signal is connected
with the link e. Of the links in this reduced train c and / are
normal crossed links, a and e have parallel cylinders ; the links b
and d are omitted. The two open cylinders 2 and 4 of the link c
have therefore higher screw motions relatively to the full cylinders
of a and e upon which they work. In order to complete the chain
it would be necessary to add the two links b and d, (which are
each in the form C~ ...\\...P + , and to make the elements in c a pair
of open prisms.
���FIR. 392.
�FIG 393.
�Robertson's steam-engine * is another mechanism of the same
kind, its leading train is represented by Fig. 392. The link a has
the form C+...\\...C+ ; the link 6, C-...\\...P+, is omitted, but c is
still left. On account of the omission of b the latter has no longer
- Artisan, vol. xxix., 1871, p. 2 ; Revue Tndustrielle, June, 1874, p. 192 ; Dingler's
Journal, 1874, vol. 213, p. 183.
�