II. SPECIAL COLLECTIONS. 383 



This improvement, consisting of new methods of applying the power of 

 steam engines to move mills for rolling and slitting iron and other metals, 

 is included in Specification of Patent, granted to' James Watt of Birmingham, 

 and dated April 28th, 1784. 



1928f. Model of Boiling Mill, driven by a connecting 

 rod, fitted with stepped sun and planet motion, and with two fly 

 wheels. 



192 8g. Model of two Tilt Hammers, at right angles to 

 each other, one hammer actuated at the tail by cams, the other by 

 lifting cams, driven by one connecting rod fitted with stepped sun 

 and planet motion. 



NOTE. Part of the above model is missing, and the helve of one tilt 

 hammer is broken. 



1928h. Model of Wheel (probably for grinding). With 

 sliding axle. 



19281. Fragment of Model (probably a pump bucket). 



1928k. Models on a Stand, of four trussed beams, probably 

 used experimentally for testing the strength of different methods of 

 trussing. 



19281. Fragment of a Model of a Frame for a Ma- 

 chine. 



1928m. Fragment of a Frame. 



1928n. Model of a Horse Mill, with roller and trough, 

 apparently designed for crushing material. 



1928o. Model of a Train of Wheels. 



1928p. Model of Beam and two connecting Bods with 

 universal motion at their upper ends, and connected to transverse 

 hinged links at their lower ends. 



1928q. Model of Beam Pumping Engine, single acting 

 and condensing, worked by tappet valve motion. 



1928r. Model of double acting Beam Condensing En- 

 gine, conical valves worked by eccentric. 



1928r. Model of inverted Cylinder, direct acting pump- 

 ing engine with tappet valve motion. 



