Printing : a practical treatise on the art of typography as applied more particularly to the printing of books (1904)
Jacobi, Charles Thomas · London : G. Bell & Sons · leaf 372
bed from the bottom. As very greatpressure is given, the sides of the press, as likewise itshead, must be of great strength, and, as a matter of course,made of iron. When it is pumped up and the requiredpressure exerted, it is held by fastening a valve, andif the press is in good order the power is… … FlG. 173. HYDRAULIC PEESS. and retained by an ordinary press with a 12-inch ram,which will take, say, double demy. If the leather collar ofthe piston becomes worn, it will cause a leak and power isthereby lost. A dial indicating the exact pressure exerted 342 PRINTING is sometimes attached to these…
