"Now the actual fact at Binner Downs, at the rate of working and power above mentioned, is that 3 bushels of coal per hour were burnt, using 13 gallons of injection-water at each stroke at 70° of heat, which was raised by its use to 104°, or an increase of 34°, which, multiplied by 13 gallons, gives 442. Mr. Watt's table for this engine and work gives 57 gallons of condensing water at 50°, heated by use to 100°. This 50° raised, multiplied by the 57 gallons of water, amounts to 2850, or six and a half times the quantity really used in the Binner Downs engine, and nearly four times the coal actually used at present. Mr. Watt further says that steam of 15 lbs. to the inch, or one atmosphere, from 1 inch of water at 212° occupies 1170 inches, and that steam of four atmospheres, or 60 lbs. to the inch, gives only 471 inches at a heat of 293°. Now deducting 50° from 212° leaves 162° of heat raised by the fire. Multiply 15 lbs. to the inch by 1700 inches of steam, and divide it by 162°, gives 138°, whereas if you deduct 50° from 293°, it leaves the increase of heat by the fire 243°. Steam of 60 lbs. to the inch multiplied by 471, being the inches of steam made by 1 inch of water divided by 243°, the degrees of heat raised by the coal, gives a product of 116; therefore, by Mr. Watt's view it appears that low steam would do one-fifth more duty than high steam, and yet Binner Downs engine in actual work performs about four times the duty given by Mr. Watt's theory and practice, with only one-sixth part of the amount of heat carried off by the condensing water, proving that high steam has much less heat, in proportion to its effective force; and this is further proved by the small quantity of condensing water required to extract its heat. "Yesterday I proved this 70-inch cylinder while working with the fire-flues round it, which flues only consumed 5 bushels of coal in twenty-four hours. The engine worked eight strokes a minute, 10-feet stroke, 11 lbs. to the inch effective force on the piston; steam in the boiler 45 lbs. above the atmosphere, consuming 12 bushels of coal in four hours, using 13 gallons of condensing water at each stroke, which was heated from 70° to 104°; but when the fires round the cylinder were not kept up, though still having the casing of hot brickwork around it, and performing the same work, burnt 17 bushels of coal in the same time of four hours, and required 15-1/2 gallons of condensing water, which was heated from 70° to 112°. You will find that the increased consumption of coal, by removing the fire from around the cylinder, was nearly in the same proportion as the increase and temperature of the condensing water, showing the experiment to be nearly correct.