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\th January, 1887. 



W. H. Patterson, Esq., M.R.I.A., in the Chair. 



Alexander B. Wilson, Esq., read a Paper on 

 POWER. 



Mr. Wilson said the subject of his remarks, " Power and 

 its Transmission," was too wide to be dealt with in the limits 

 of such a paper, except in a very brief way. He had intended 

 to deal particularly with the subject of compressed air as a 

 power, but, fearing that the question would perhaps be too 

 strictly technical and uninteresting if treated alone, and 

 having regard also to his own connection with the Bir- 

 mingham Compressed Air Company, he had concluded to 

 deal with the matter in a more general way, rather than with 

 especial regard to the most interesting advances in engineering 

 which are going on in the Midland metropolis. Mr. Wilson 

 then proceeded to explain the different terms used in con- 

 nection with power, as " horse-power," " foot tons," &c. James 

 Watt and the engineers of his time adopted the expression 

 " horse-power " as the most convenient term by which to 

 convey to the mill and mine owners the capabilities of their 

 engines. The original value of a " horse-power " was based on 

 the work it was estimated a healthy horse could do in a working 

 day, and it was therefore based on two quantities — work and 

 time. In engineering a horse-power consists in the power to 

 raise 33,000 pounds one foot in one minute, or 19,800,000 pounds 

 one foot in a working day of ten hours. This is far too high 

 an estimate of the work of a horse, for it would mean the 

 capability of raising four tons in one day of ten hours to a 

 height equal to that of Divis. 

 Mr. Wilson then went on to speak of the power developed 



