II. SPECIAL COLLECTIONS. 447 



II. SPECIAL COLLECTIONS. 



COLLECTION OF THE ORIGINAL MODELS OF STEAM ENGINES AND 

 OTHER MACHINES OF JAMES WATT. PRESENTED TO THE 

 SOUTH KENSINGTON MUSEUM BY MESSRS. J. WATT AND Co. 



1928a. Imperfect Model of method of converting recipro- 

 cating into rotatory motion by means of teeth or pins fixed to the 

 connecting rod, which gear with the teeth in a wheel, and cause 

 it to revolve. Some point of the connecting rod is guided by 

 a pin, moving in a groove, so as to keep the teeth or pins always 

 engaged in the teeth of the wheel. 



This method of converting reciprocating into rotatory motion is included 

 in Specification of Patent granted to James Watt, dated October 25th, 1781. 



1928b. Two Fragments of a Model, consisting of wood 

 rods with oval holes geared internally, and apparently belonging 

 to one of the models selected from the Soho Works by the late 

 Sir Francis Smith, as an illustration of one of the methods of 

 converting reciprocating into circular motion. 



1928c. Model of Grinding Mill, 6 pairs of stones in two 

 sets of 3 pairs each, each set driven by a spur wheel with bevil 

 gearing. The two fly wheels are connected and driven by pin and 

 connecting rod. 



1928d. Model of Grinding Mill, with six pairs of stones, 

 in two sets of three pairs each. Each set driven from one spur 

 wheel by bevelled gearing. 



The two fly wheels are connected, and driven by one connecting rod, fitted 

 with two sets of stepped sun and planet wheels. 



1928e. Model of Rolling and Slitting Mill, driven by 

 two connecting rods, on one beam, and fitted with sun and planet 

 stepped gearing. 



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

 steam engines to drive 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 Rolling Mill, driven by a connecting 

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

 wheels. 



1928g. 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. p ar t of the above model is missing, and the helve of one tilt 

 hammer is broken. 



