Letter. Boulton & Watt [Soho] to Andrew Collins (Birmingham).

Answers by Boulton and Watt to Mr Mr Olde’s queries Octr 30th 1780
1. A Wine Hogshead contains 8 1/13 cubic feet, therefore 25 Hogsheads contain 208 cubic feet, which divided by 10, the strokes the Engine would make pr minute, gives 20 8/10 feet pr stroke which will require a pump of 21½ inches diar in the working barrels To work such a pump 20 feet high, will require a Cylinder of 21 inches diar with a stroke 8 feet long. An Engine of that size with the pump and house Costs when erected in this Country about £500 or £600 we cannot say exactly how much because we never undertake Engines piece work and the price varys according to the situation.
2dly A 21 inch Cylinder going at the above rate will use about 10 bushels of Newcastle coal in 12 hours, but by good management and good coals may be made to use rather less—10 bushels weigh about 840 english pounds.
3d this Question cannot be answered untill Mr Boulton returns, in general we cannot undertake engines for the Continent on the same terms as at home they being attended with more than double trouble, and we should not at any rate engage in such a matter without some intelligent person could be sent here to receive instructions as to what we would require for our premium I, (J Watt) cannot alone pretend to fix but if it were in London and the machine were to have close work the premium would ammount to above £100 pr year reckoning the Machine to go only 310 days and 12 hours in every day.
When Mr Boulton returns if Mr Olde should find from the above that such a machine is likely to answer a good end to him we shall write more fully.
Boulton & Watt
Birmm: Octr 30th 1780