Figure 43. — Ackermann steering linkage of 

 1818, currently used in automobiles. This 

 linkage was invented by George Lankensperger, 

 coachmaker to the King of Bavaria. From 

 Dinglers Polytechnisches Journal ( 1 820, vol. i , pi. 7) . 



tion in London.'"' Willis' comments on the mecha- 

 nism are reproduced in figure 44. I hope that Sir 

 Joseph Whitworth (1803-1887) will be remembered 

 for sounder mechanical contrivances than this. 



Mechanisms in America, 1875-1955 



Engineering colleges in the United States were oc- 

 cupied until the late 1940's with extending, refining, 

 and sharpening the tools of analysis that had been 

 suggested by Willis, Rankine, Reuleaux, Kennedy, 

 and Smith. The actual practice of kinematic synthesis 

 went on apace, but designers often declined such help 

 as the analytical methods might give them and there 

 was little exchange of ideas between scholars and 

 practitioners. 



The capability and precision of machine tools were 

 greatly enhanced during this period, although, with 

 the exception of the centerless grinder, no significant 

 new types of tools appeared. The machines that were 

 made with machine tools increased in complexity and, 

 with the introduction of ideas that made mass produc- 



tion of complex mechanical products economically 

 feasible, there was an accelerating increase in quan- 

 tity. The adoption of standards for all sorts of com- 

 ponent parts also had an important bearing upon the 

 ability of a designer economically to produce mecha- 

 nisms that operated very nearly as he hoped they 

 would. 



The study of kinematics has been considered for 

 nearly 80 years as a necessary part of the mechanical 

 engineer's training, as the dozens of textbooks that 

 have been published over the years make amply clear. 

 Until recently, however, one would look in vain for 

 original work in America in the analysis or rational 

 synthesis of mechanisms. 



One of the very earliest American textbooks of kine- 

 matics was the 1883 work of Charles W. MacCord 

 (1836-1915), who had been appointed professor of 

 mechanical drawing at Stevens Institute of Technol- 

 ogy in Hoboken after serving John Ericsson, designer 

 of the Monitor, as chief draftsman during the Civil 

 War."" Based upon the findings of Willis and Ran- 

 kine, MacCord's Kinematics came too early to be in- 

 fluenced by Kennedy's improvements upon Reul- 

 eaux's work. 



When the faculty at Washington University in St. 

 Louis introduced in 1885 a curriculum in "dynamic 



'"'The quick-return mechanism (British Patent 12907, 

 December 19, 1849) was perhaps first publicly described in 

 Charles Tomlinson, ed., Cyclopaedia of Useful Arts and Manu- 

 factures, London, 1854, vol. 1, p. cxliv. 



u" A biographical notice and a bibliography of MacCord 

 appears in Morton Memorial: A History of the Stevens Institute of 

 Technology, Hoboken, 1905, pp. 219-222. 



PAPER 27: KINEMATICS FROM THE TIME OF WATT 



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