The blowing apparatus is singularly ingenious, and is certainly as economical of manual labor as a blowing arrangement depending on manual labor well can be.  A section of the bellows forms the portion to the right of Fig. 1, showing tuyere forming the connection between bellows and furnace.  It consists of a circular segment of hard wood, rudely hollowed, and having a piece of buffalo hide with a small hole in its center tied over the top.  Into this hole a strong cord is passed, with a small piece of wood attached to the end to keep it inside the bellows, while the other end is attached to a bent bamboo firmly fixed into the ground close by.  This bamboo acts as a spring, drawing up the string, and consequently the leather cover of the bellows, to its utmost stretch, while air enters through the central hole.  When thus filled, a man places his foot on the hide, closing the central hole with his heel, and then throwing the whole weight of his body on to that foot, he depresses the hide, and drives the air out through a bamboo tube inserted in the side and communicating with the furnace.  At the same time he pulls down the bamboo with the arm of that side.  Two such bellows are placed side by side, a thin bamboo tube attached to each, and both entering the one tuyere; and so by jumping on each bellows alternately, the workman keeps up a continuous blast.

[Illustration:  Fig. 2.—­PLAN OF INDIAN BLAST FURNACE AND BLOWING MACHINE.]

The Figs. 1 and 2 are taken from sketches, and the description from particulars, by Mr. Blandford, who was for some years on the Geological Survey of India, and had exceptional opportunities in his journeyings of observing the customs and occupations of the Indian iron smelters.  The blowing machine is an especially wonderful and effective machine, and was first described and illustrated by Mr. Robert Rose, in a Calcutta publication, more than half a century ago.  He also had seen it used in iron making in India.—­Colliery Guardian.

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WOOD OIL.

Wood oil is now made on a large scale in Sweden from the refuse of timber cuttings and forest clearings, and from stumps and roots.  Although it cannot well be burned in common lamps, on account of the heavy proportion of carbon it contains, it is said to furnish a satisfactory light in lamps specially made for it; and in its natural state it is the cheapest illuminating oil.  There are some thirty factories engaged in its production, and they turn out about 40,000 liters of the oil daily.  Turpentine, creosote, acetic acid, charcoal, coal-tar oils, etc., are also obtained from the same materials as the wood oil.

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SOAP.

By HENRY LEFFMANN, M.D.