Figure 4. — Grain mill, 1588, showing con- 

 version of motion of the operating bars from 

 oscillation to rotation. Note the fly-weights, 

 predecessors of the flywheel. From Agostino 

 Ramelli, Le Diverse et Artificiose Machine (Paris, 

 1588, pi. opposite p. 199). 



your engine would require money, very accurate 

 workmanship and extensive correspondence to make 

 it turn out to the best advantage and that the best 

 means of keeping up the reputation and doing the 

 invention justice would be to keep the executive part 

 of it out of the hands of the multitude of empirical 

 engineers, who from ignorance, want of experience 

 and want of necessary convenience, would be very 

 liable to produce bad and inaccurate workmanship; 

 all of which deficiencies would aflfect the reputation of 



the invention."' Boulton expected to build the 

 engines in his shop "with as great a difference of 

 accuracy as there is between the blacksmith and the 

 mathematical instrument maker." The Soho Works 

 of Boulton and Watt, in Birmingham, England, 

 solved for Watt the problem of producing "in great" 

 (that is, in sizes large enough to be useful in steam 

 engines) the mechanisms that he devised.' 



The contributions of Boulton and Watt to practical 

 mechanics "in great" cannot be overestimated. 

 There were in the 18th century instrument makers 



3 James P. Muirhead, The Origin and Progress of the Mechanical 

 Inventions of James Walt, London, 1854, vol. 1, pp. 56, 64. 

 This work, in three volumes, contains letters, other documents, 

 and plates of patent specification drawings. 



PAPER 27: KINEMATICS FROM THE TIME OF WATT 



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