Scientific amusements . m:— Place. Height above levelof the sea—Feet. Barometer meanheight. Boiling point ofwater, Fahr. Quito 9,5417,4716,8084,7381,221. 2130 20-7S22-52 23-0724-9628-542969 30-00 194-2198-1199-2203-0209-5211-52I2-0 St. Gothard Garonne (Pyrenees) Geneva Paris (ist floor) Sea level [The difference for a degree depends upon the height,varying between 510 and 5 90 feet, according to theelevation reached. The approximate height of a mountaincan be found by multiplying 530by the number of degreesbetween the boiling point and 212°. In some very elevatedregions travellers have even fa
Scientific amusements . m:— Place. Height above levelof the sea—Feet. Barometer meanheight. Boiling point ofwater, Fahr. Quito 9,5417,4716,8084,7381,221. 2130 20-7S22-52 23-0724-9628-542969 30-00 194-2198-1199-2203-0209-5211-52I2-0 St. Gothard Garonne (Pyrenees) Geneva Paris (ist floor) Sea level [The difference for a degree depends upon the height,varying between 510 and 5 90 feet, according to theelevation reached. The approximate height of a mountaincan be found by multiplying 530by the number of degreesbetween the boiling point and 212°. In some very elevatedregions travellers have even failed to boil potatoes.] The boiling point of liquid may be altered by mixingsome substance with it; and although such a substance assawdust would not alter the boiling point of water, yet ifthe foreign matter be dissolved in the liquid it will alter 22 HEAT. summer. The only inconvenience attending it is theemployment of sulphuric acid, of which a considerablequantity is used to absorb the vapour from the water, as. already referred to. If proper precaiitions are taken,however; there will be no danger in using the apparatus. The mode of proceeding is as follows :—The bottle fullof water is joined to t!ie air-pump by a tube, and after afew strokes the water is seen in ebullition. The vapour ARTIFICIAL ICE. 23 thus disengaged traverses an intermediate reservoir filledwith sulphuric acid, which absorbs it, and immediatelycondenses it, producing intense cold. In the centre ofthe liquid remaining in the carafe some needles of icewill be seen, which grow rapidly, and after a few morestrokes of the pump the water will be found transformedinto a mass of ice. This is very easy of accomplishment,and in less than a minute the carafe full of water will befound frozen. The problem for the truly economical formation of iceby artificial means is one of those which have occupiedchemists for a long time, but hitherto, notwithstandingall their efforts, no satisfactory conclusion has been
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Keywords: ., bookcentury1800, bookdecade189, booksubjectscientificrecreations
