Iron Age - Volume 103 - Page 344 - Google Books Result
Describes a porta ble hoisting machine , built in sizes from 6 to 20 ft . in height and a line of grinding , pulverizing , and to longer life , is the construction of all surfaces Lists and are included . illustrates a line of belt or hand power machines for The capacity of the elevators range from 616 supplied . to 80 tons per hour .