Item 225 - William Whewell to Richard Jones

4 pp.

Trinity Lodge - WW thinks RJ will get some good suggestions from Willis [Robert Willis] if he puts his case to him. This is what occurs to WW: 'In every machine or rather in every mechanical work you have three things to consider - moving power, train of mechanism connecting the power with the work - work done'. RJ's 'question seems to be how much the value of the work done exceeds the value of the moving power. I reply, it exceeds it by the value of the mechanism, at least, otherwise people would not acquire the mechanism'. WW gives more details giving Willis's example of a knife grinder. WW's axiom is 'the value of the work done must be the value of the moving power + the value of the machinery'. The 'productive power of nations must be compared by comparing the moving forces + the whole quantity of working mechanism; for the latter would not exist if it did not add its own value to that of the moving frame'. Willis and WW 'agreed to call the measure of moving power Labouring Force - an expression which has considerable advantages - the French term is Travail'. The University has petitioned for the Welsh Bishoprics [see WW to RJ, 2 Dec. 1842].