4 VARIOUS INVENTIONS. 



diameter cylinder, with a 3-feet stroke, drawing 100 -gallon 

 barrels, twenty-four every hour, 80 yards, burning 5 cwt. of 

 coal in twenty-four hours. 



" This work it did with very great ease. I believe you will 

 find this an exceeding good duty for a 5^-inch cylinder engine. 

 " Below I send a copy of Mr. Homfray's and Mr. Wood's 

 letters to me : 



" Mr. Homfray's, of the 10th September. ' Our great engine 

 goes on extremely well here, nothing can go better ; the piston 

 gives no trouble ; it goes about three weeks, and we work it with 

 blacklead and water ; the cylinder is as bright as a looking- 

 glass ; it uses about 2 Ibs. of blacklead in a week ; about once 

 in twelve or fifteen hours we put a small quantity of blacklead, 

 mixed with a little water, through the hole in the cylinder 

 screw, and we never use any grease. We rolled last week 140 

 tons of iron with it, and it will roll as fast with the both pair of 

 rolls, as they can bring to it.' 



" Mr. Wood's letter, September 12th. ' We are going on, as it 

 is likely we always shall, in the old dog-trot way, puddling and 

 rolling from the beginning of the week till the end of it. Your 

 engine is the favourite engine with every man about the place, 

 and Mr. Homfray says it is the best in the kingdom.' 



" I have not the smallest doubt but that I can make a piston 

 without any friction or any packing whatever, that needs not to 

 have the cylinder screw taken up once in seven years. It is a 

 very simple plan, and will be perfectly tight ; it is by restoring 

 an equilibrium on both sides of the piston. I expect to see you 

 in London soon, and then w r ill give you the plan for inspection 

 before I put it in practice. 



"I am very much obliged to you for recommending these 

 engines in Cornwall, but you have not stated in what manner 

 they are to be applied ; whether to work pumps, or barrels, or 

 both. They may be made both winding and pumping engines 

 at the same time, if so required. 



"A rotative engine will cost more than an up-and-down- 

 stroke, on account of the expense of the fly-wheel and axle. 

 An engine capable of lifting 180 gallons of water per minute 

 20 fathoms would cost, when complete and at work, patent 



