This allowed a shorter train and stronger wheelwork to be used, securing more certain action, and involving less risk of derangement.
Alexander Bain in 1846 suggested enclosing the wheelwork in the rotator.
In Thomas Walker's harpoon or frictionless log, introduced in 1861, the wheelwork was enclosed in a cylindrical case of the same diameter as the body of the rotator or fan, and the latter was brought close up to the register, forming a compact machine and avoiding the use of the 6-ft.
The case A contains the registering wheelwork and a sounding bell.
Case A contains the wheelwork, and case E the spindle and steel ball FIG.
In wheelwork of this kind the contact of each pair of teeth commences at the foremost end of the helical front, and terminates at the aftermost end; and the helix is of such a pitch that the contact of one pair of teeth shall not terminate until that of the next pair has commenced.
The forests contain a great variety of useful woods, affording excellent timber; among the commonest trees are the yellow wood, which is also one of the largest, belonging to the yew species; black iron wood; heavy, close-grained and durable stinkhout; melkhout, a white wood used for wheelwork; nieshout; and the assegai or Cape lancewood.