8 REPORT— 1888. 



But there are prime taovers and prime movers — those of small 

 dimensions, and employed for purposes where animal power or human 

 power might be substituted, and those which attain ends that by no 

 conceivable possibility could be attained at all by the exertion of muscular 

 power. 



Compare a galley, a vessel propelled by oars, with the modern Atlantic 

 liner ; and first let us assume that prime movers are non-existent and 

 that this vessel is to be propelled galley-fashion. Take her length as 

 some 600 feet, and assume that place be found for as many as 400 oars 

 on each side, each oar worked by three men, or 2,400 men ; and allow that 

 six men under these conditions could develop work equal to one horse- 

 power : we should have 400 horse-power. Double the number of men, 

 and we should have 800 horse-power, with 4,800 men at work, and at 

 least the same number in reserve, if the journey is to be carried on 

 continuously. Contrast the puny result thus obtained with the 19,500 

 horse-power given forth by a large prime mover of the present day, 

 such a power requiring, on the above mode of calculation, 117,000 

 men at work and 117,000 in reserve; and these to be carried in a 

 vessel less than 600 feet in length. Even if it were possible to carry 

 this number of men in such a vessel, by no conceivable means could 

 their power be utilised so as to impart to it a speed of twenty knots 

 an hour. 



This illustrates how a prime mover may not only be a mere substitute 

 for muscular work, but may afEord the means of attaining an end, that 

 could not by any possibility be attained by muscular exertion, no 

 matter what money was expended or what galley-slave suffering was 

 inflicted. 



Take again the case of a railway locomotive : from 400 to 600 horse- 

 power developed in an implement which, even including its tender, does 

 not occupy an area of more than fifty square yards, and that draws us at 

 sixty miles an hour. Here again, the prime mover succeeds in doing that 

 which no expenditure of money or of life could enable us to obtain from 

 muscular effort. 



To what, and to whom, are these meritorious prime movers due ? I 

 answer : to the application of science, and to the labours of the civil 

 engineer, using that term in its full and proper sense, as embracing all 

 engineering other than military. I am, as you know, a Civil Engineer, 

 and I desire to laud my profession and to magnify mine office ; and I know 

 of no better means of doing this than by quoting to you the definition of 

 ' civil engineering,' given in the Charter of The Institution of Civil 

 Engineers, namely, that it is ' the art of directing the great sources 

 of power in Nature for the use and convenience of man.' These words 

 are taken from a definition or description of engineering given by one of 

 our earliest scientific writers on the subject, Thomas Tredgold, who com- 

 mences that description by the words above quoted, and who, having given 



