low temperature (-15°), the author could not detect ammonia in snow.
Cultivation by Steam.—At an agricultural meeting, recently held in Scotland, some interesting statements were made respecting the origin, progress, and results of cultivation by steam in Europe. In 1855, a Mr. John Fowler, of Essex County, England, started his first steam-plough. Now, in Great Britain, there are single establishments for manufacturing steam-ploughs, so extensive that they furnish constant employment for not less than 1,200 men. In England, between 400 and 500 sets of steam-ploughs, held, some by companies and others by individual owners, are worked for hire, and are found to be a profitable investment. A tract of 500 acres, near London, so unproductive that it could not be rented for $3 per acre, was bought by an enterprising farmer, who removed the fences, under-drained, and, with a steam-plough, put the whole into grain-crops. Last year, after allowing 10 per cent, on the money invested in the land, his clear profits were $18,000. The soil he thus improved by deep steam-ploughing is a stiff clay that could not be profitably worked by horse-power. Another tract of 5,000 acres, that had been regarded as worthless, was bought by a farmer who ploughed it with steam-power to the depth of 3 feet, and was rewarded by crops of astonishing thrift. In Scotland, cultivation by steam is becoming general, and producing results equally marvellous. Joint-stock companies are investing in land and steam-machinery, and securing large dividends, while individual farmers have invested from $6,000 to $10,000 in steam-machinery with very profitable results. In Germany also steam-power is working a revolution in agriculture.
It was also stated that the Pasha of Egypt now employs on his extensive domain 400 steam-ploughs, and is building "on his farm" 400 miles of railway, and, for transporting and manufacturing the raw material produced, has ordered thirty locomotive-engines and $3,000,000 worth of sugar-machinery.
Perhaps the most successful cultivator by steam in America is Mr. E. Lawrence, of Magnolia Plantation, parish of Plaquemine, Louisiana. In a letter to the Agricultural Department, he speaks of the results of his trial of the steam-plough as follows:
"Two hundred and twenty acres of my cane-crop, 140 acres of which were plant-canes, and 80 acres first-year rattoons, were, I believe, as thoroughly ploughed and cultivated by steam as could be desired. The 80 acres of first-year rattoons, grown from the stubbles of the steam-ploughed cane planted in a similar manner last year, were barred off and well dug in the month of March, then subsoiled and cultivated by steam precisely as the plant-canes. The yield was over 2,500 pounds of sugar to the acre."
Mr. Lawrence closes his letter with the prophecy:
"Necessity will soon compel us to take a 'new departure.' The constant increase of immigration and population in the grain-growing States of our country will soon demand a better cultivation and increased production. In England, steam-ploughing has increased the yield of wheat from 16 bushels to 28 bushels to the acre.
"I do not believe the agricultural interest of our country can much longer turn a deaf ear to this last and greatest achievement of steam—its successful application to the cultivation of the soil. It has broken the yoke and lifted the burden which, for ages, held both man and beast in bondage, ameliorating their condition by making that which was most onerous easy and attractive; it has elevated labor, and dignified the plough."
Ozone by a New Process.—An apparatus for manufacturing ozone, patented by Dr. Loew, is mentioned in the Journal of the Franklin Institute. Some time since Dr. Loew observed that cold air blown through a flame is in part converted into ozone, and his apparatus is constructed with a view to turn this observation to practical account. It consists of a number of Bunsen burners, set up in a row, with an equal number of horizontal tubes at some distance above the burners. The cold air is blown through the tubes against the flames, and is then collected, in the shape of ozone, by a number of funnels placed on the opposite side of the flames. The ozone is to some extent contaminated byand nitrous acid.