II: THE EFFECT. We will now in due order consider the effect obtained at the recent test made with this machine.
§ 14. The cylinder of the machine is 9 feet long and 36 inches in diameter; the depth from which it draws water is 31 fathoms or 186 feet; the pump-pipe, by means of which the fire-machine draws water, is 9 inches in diameter; the lift of the machine when the springs within and without the house are pressed down is 7 feet; but as this only takes place when the fire beneath the boiler is very strong, the effect of the machine will have to be put down only to a 6 feet lift, and though the machine in reality makes 14, 15, 16 strokes or lifts a minute, only 14 lifts will here be taken into account; For the sake of those who are not used to these calculations and wish to measure the effectiveness of our machine, I have brought with me from my last visit to Dannemora a spare pump of the same calibre or diameter as the three sets of the mine; out of this pump I have made a vessel, accurately one foot high, and have since then in the presence of many onlookers filled and measured this vessel, and thus proved that it contains 6 kannor of water.
§ 15. I have also made in the same way out of one piece of a worn-out pump, taken from the force-work, (the force-work draws water from the basin 45 feet up into the resevoir of the engine-house) a similar vessel, one foot high and 8 inches in diameter, which contains 4 kannor water, and demonstrated how the effect of the machine may be calculated.
The lift of the machine takes 6 feet every foot contains 6 kannor ____________________ 36 kannor The machine makes 14 strokes a 14 minute ____________________ 144 36 ____________________ 504 kannor a minute 60 minutes _____________________ 48) 30240 kan. an hour _____________________ 630 tunnor of water 24 hours [an hour _____________________ 2520 1260 _____________________ 15120 tunnor of water in 24 hours.
§ 16. As one kanna of water wighs 6 skålpund, 8 lod, V. W. (Vide his Royal Maj: s Gracious ordinace concerning measurements and weights, 1773.) the machine will consequently draw 189000 skålpund of water in an hour. The machine delivers 30240 kannor every hour
6 1/4 skålpund _______________ 181440 7560 _____ 400) 189000 skålpund _____ 472 skeppund, 10 lispund water
§ 17. The force-work has a lift of 3 feet, 3 inches and the metal pump-barrel is 8 inches in diameter; the water-column is 8 inches in diameter and I foot high, thus containing 4 kannor of water,--as has already been demonstrated above. From this follows that when the lift of the force-work is 3 feet
every foot contains 4 kannor water ______ 12 kannor 14 lifts ______ 48 12 ______ 168 kannor a minute 60 minutes __________ 48) 10080 kannor in an hour __________ 210 tunnor an hour 24 hours ______ 840 420 ______ 5040 tunnor water in 24 hoursThe force-work is, as a matter of course, able to deliver 63000 skalpund V.W. per hour, because 10080 kannor per hour=
10080 6 1/4 skålpund _____________ 60480 2520 _____________ 440) 63000 skålpund ______________The force-work delivers consequently 157 skeppund, 10 lispund water per hour.
§ 18. If one now adds to the previous quantity of water, which the machine draws from the mine in 24 hours, namely 15020 tunnor, the quantity drawn by the force-work 5040, the total amount will be 20060 tunnor water per twenty-four hours which the machine is able to draw.
And if one furthermore adds to the weight of the water which the machine draws from the mine every hour, namely 472 skeppund 10 lispund, the weight which the force-work delivers every hour, namely, 157 skeppund 10 lispund, the total amount will be 630 skeppund; an incredible weight of water which the machine is able to deliver every hour.
§ 19. We have now demonstrated the actual effect of the Dannemora fire- and air-machine, and we hope that the kind reader will graciously not object to an account of the results obtained by the fire- and air-machine which has been constructed in the Royal mining town Königsberg in Hungary. This account, which we cite in the following paragraphs, is made by the imperial gun-founder, Mr Leopold in Vienna, of whom Herr Gerhard Meijer says that he has a greater renown abroad than in his own country, though the smallest evidence proving his skill, amongst many others of his works, will certainly not be the cylinder he made for the Dannemora fire-machine. (Among 14 metal and almost as many iron cylinders, known to me, I have not been able to discover a more perfect and absolutely faultless cylinder than this, though all the others have been smaller than the one at Dannemora.)
Extract from the before-mentioned account dated Vienna the 25th of June 1733, running, according to the letter, as follows.
§ 20. "Because of the five years experience obtained in the Royal mining town Königsberg in Hungary, showing how by a fire-machine a great saving in the expenditure of drawing water from the mines can be made as compared with the old way of drawing water by means of horses, which the following circumstances will fully prove, the August Imperial Court Chamber or Ministry of Mines has decided to replace all the horses, of which now 500 are being used, with 5 fire- and air-machines, notwithstanding the fact that the fire-wood needed to keep these machines going is scarce and expensive.
"The fire machine at Königsberg has a cylinder, 7 1/2 feet high and 28 inches in diameter. The depth out of which the machine has to draw water is 30 klafter or 180 feet;
"The capacity of the pump-pipes enables the fire-machine, with a lift of 6 feet, and 14 to 15 strokes or lifts in a minute, to draw 117,600 skålpund water in an hour. (This machine, which is little more than 1/3 smaller than the one at Dannemora, has also delivered 71,400 skålpund water less in an hour than the Dannemora machine.) As, however, a certain Principal Mining Corporation in Königsberg seriously doubted, whether this fire-machine alone would be able to draw all the water from the mine, they decided to keep a horse-whim (in Hungary generally called a "wasser Ross-Geipel") (or a machine for pumping-up water from the same depth as the fire-machine with horses) going as well, thus hoping to ascertain by experiment and close observation the difference, not only in power but also in cost, between these two artifices.
"The horse-whim or artifice has been driven or worked by 8 pairs of horses, which have been relayed 4 times in 24 hours, so that this artifice has actually been drawn by 32 pairs of horses for 24 hours.
"This horse-whim or artifice has drawn 25 feet water per minute by means of two sets of pumps 8 inches in diameter, with a lift of 2 1/2 foot, which makes altogether 5 feet, and 5 lifts in a minute.
"Even if one allows the fire-machine only 13 strokes or lifts of 6 feet, it will be easily seen how, by subtracting the 25 feet of water which the horse-artifice is lifting in the same time as the fire-machine is lifting 78 feet, the fire-machine has actually been lifting 53 feet of water more than the horse-artifice.
"As to the cost, the horses with their apparatus have been drawing 900 imperial gulden a month.
"Whilst the fire-machine, with all its staff and firewood,--one gulden being the estimated cost of one klafter--has drawn only 400 imperial gulden a month; which makes such a difference in effect as well as in cost that the mining corporation, as soon as it was able to ascertain this, decided to let the fire-machine operate alone."
§ 21. Mr Isaac Potter, an Englishman who has constructed this fire-machine, has been granted an imperial subsidy of 8800 daler copper yearly.
It will now be of interest to compare the power as well as the effect of the Dannemora fire-machine with that of the Königsberg of Hungarian machine.
The Hungarian machine has a cylinder 7 1/2 feet high and 27 inches in diameter; the piston-area being 616 square inches, and the power equal to 12937 1/2 skålpund or 32 skeppund, 6 lispund, 17 1/2 skålpund. The Dannemora machine again has a cylinder 9 feet long and 36 inches in diameter; the piston-area being 1018 2/7 square inches, and the power equal to 21575 skålpund, or 53 skeppund, 18 lispund 15 skålpund. This shows that the Dannemora-machine is twice as powerful as the Hungarian machine. The pump-tubes are 8 inches in diameter, and the depth of the mine 30 klafter or fathoms, the water-column weighs consequently 4500 skålpund, or 11 skeppund 5 lispund, v. weight. The pump-tubes in the mine are 9 inches in diameter and the depth 37 fathoms, the water-column weighs consequently 8425 skålpund, or 21 skeppund, I lispund, 5 skålpund, v. weight. The machine delivers 78 feet water per minute, which makes --considering that one foot of an 8 inches pump contains four kannor of water,--312 kannor per minute. One foot of a 9 inches pump contains 6 kannor . The machine is consequently delivering 504 kannor of water per minute. This machine draws 117600 skålpund per hour. This again delivers 189000 skålpund or consequently 71400 more per hour. The fire-machine in Hungary is doing more work in 24 hours than 3 horse-whims of 32 pairs of horses each, which makes altogether 192 horses in 24 hours. The Dannemora machine is doing as much work in 24 hours as 66 horse-whims, each drawn by 4 pairs of horses, or altogether 528 horses in 24 hours.
§ 22. It will certainly seem strange to many readers of this book that the Dannemora fire-machine should be able to draw the same quantity of water in 24 hours as 66 horse-whims, each drawn by 4 pairs of horses. I will however try to explain how this can be ascertained. The basis for the calculations is easy to find, for if I take the quantity of water which the machine is able to draw in 24 hours and compare it to what 66 horse-whims are able to draw, it will soon be found which side has got the largest quantity.
§ 23. A horse-whim at Dannemora, drawn by two pairs of horses, can not draw more than 60 big tubs of water in 12 hours, even if the horses are trotting. (Generally the horses go at a footpace, and it is pitiable to look at them especially in spring-time--in autumn and winter again the short days prove a great hindrance.) It is also to be taken into account that the horses must be allowed 12 hours complete rest.
§ 24. A big tub contains 120 kannor when it is quite filled to the brim. But although it seldom happens that a tub is filled to more than 2/3 of its capacity, I will, however, assume that 60 such tubs, quite filled with water, are drawn in a day or 120 big-tubs in 24 hours
120 kannor water in each tub 120 tubs ____________ 2400 120 ____________ 48) 144000 ____________ 300 tunnor in 24 hours.Which constitutes a larger quantity of water than any horse-whim is able to draw; it has already been proved that the fire-machine is able to draw 20060 tunnor of water, and that 66 horse-whims draw each 300 tunnnor of water in 24 hours, or altogether 19800 tunnor which is still 260 tunnor less than the fire-machine.
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