2. Drawing ores and coals.
3. Driving cotton machinery.
4. Paper mills.
5. Thrashing mills.
6. Corn mills.
7. Iron manufactures, &c.
1. Raising of means of a single steam engine acting expansively 230,000 cubic feet of water can be raised one foot high by one bushel of coals ; and an engine ofone horse power working eleven and a half hours daily will raise 280,000 cubic feet of water one foot high in a day. It will cost 81. per annum, for each horse power, to return the first cost and repairs. lit raising water the stroke of a pump should not exceed eight feet, nor its diameter four teen inches, and the velocity of the piston should not be greater than ninety-eight times the square root of the length of the stroke.
The quantity of water in cubic feet delivered at one stroke of a pump in the best order is .00518 1 being the length of the stroke, and d the diameter of the pump in inches. The following table will show the quantity of work performed in 1826, at Wheel Hope, by one of the best Cornish engines made by Mr. Grose. The numbers are taken from a monthly report.
coals when working in the best manner. The average however, will be 113 bushels. The power required to grind and dress a Winchester bushel of wheat per hour is 31,000 pounds raised one foot in a minute. The velocity of the circumference of the mill-stone should be 23 feet per second, and with that velocity a pair of 5 feet stones should grind 4 or 5 bushels per hour, according to the state of the grain.
7. Iron Nanufactures.•--In the iron manufactures the steam engine is applied to blowing machines, forge hammers, rolling, flatting and slitting mills. See our Articles BLOWING Machinery and Trios.
Many of the other applications of steam will be learned from the following table given by Mr. Cleland, and showing the quantity of steam power used in Glasgow in April 1825.
2. Drawing Ores and Coals.---The engines used for this purpose are double engines from twenty to thirty horse power. From three to seven cwt. is generally raised at once; and as the work is irregular, from stoppages and changes of motion, one pound of coals raises only about 70,000 pounds of ore.
3. Driving Cotton Machinery.---Double acting engines
working expansively are best fitted for cotton mills. One horse power will drive one hundred spindles with cotton yarn and the preparatory machinery. The same power will work twelve power looms with pre paration. If the day's work is eleven hours, ninety pounds of the best caking coal will be required for each horse power.
4. Paper beating machine requires a seven horse power, and the new machines for making paper a two or a two and a half 5. Thrashing Mills.---Engines from 4 to 6 horse power are generally used. The feeding rollers per form from 35 to 473 revolutions per minute, their diameter is 33 inches, and their length from 4 to 5 feet. The straw rollers revolve 30 times per minute, and their diameter is 3A feet. The drum revolves 300 times in a minute, and is 3 feet in diameter. The quantity of wheat thrashed by a machine with feeding rollers 4 feet broad, varies according to its quality from 12 to 24 Winchester bushels per hour, and the quantity of oats per hour from 16 to 30 bushels. The power required is 100,000 pounds raised one foot per minute for thrashing alone, and 183,000 when win nowing machinery is also wrought. Each inch of the straw receives three strokes of the beaters. The stroke should be made with a velocity of 55 feet per second, or the beater should move 3300 feet per minute.
G. Corn Mills.---The double expansive engine is best fitted for corn mills. With low pressure steam it should grind 14 bushels of wheat for each bushel of - In 1824 upwards of 200 steam engines were used in Manchester.
Mr. Cleland has added to the above interesting docu ments, the following comparison of the price of coals consumed by steam engines and the keep of horses.
A heavy horse working 10 hours will consume 15 lbs. avoirdupois of oats, and 14 lbs. of hay per day. An engine of 30 horse power, working 10 hours per clay in a mill, will consume, on an average or summer and winter, about 4 tons of coal dross. The steam boat Toward Castle, from Glasgow to llothsay, and back again, a distance of about 80 miles, consumes 54 tons of hard coal in 12 hours.