The daily morning journal and courier., 1902-07-01

lequivalent to nearly 9,U0O horse power Iper day If ten hours for power for man ufacturing purposes.
 The food wastes of New York City ar disposed of by what is known as the Arnold utilization process. which is, briefly, steam digestion and separa- tion of the cooked product into greases land fertilizer filters. The greases are all. or nearly all, shipped abroad and, it is believed, refined and separaiei into several grades, such as glyccrine. I'd oil, lard oil and inferior grades IL is not known that refineries in this cOun- try are as yet able to handle what is known as garbage grease, as the secret of the trade seems to be held abroad The solids after being dried and screen ed are sold to the various manufactur- CTS of complete fertilizers, and by them made up into grades which seem to be particularly adapted for use in the cot ton belt.
 The process of utilization employed in New York is as follows: The gar bage is delivered on the scOws located along the water front and lowed to a place of final disposition, which is at an average distance of about 25 miles from the dumps. It is there unloaded and placed immediately in steam-tight di- gesters and treated by steam under pressure varying from 30 to so pounds for about eight hours, the vapors of cooking being condensed and not per mitted to reach the outer air. The cooked matter is then discharged from the digester into receiving tanks, and from the receiving tanks goes to press es where the grease, together with a greater part of the water, is separated from the solids. The remainder of the moisture is taken from the solids in either steam or hot-air dryers. The grease and water are run into tanks or traps, and after gravity separation the grease is skinned off. partially cleansed, and barrelled for shipment. The solids taken from the dryers are put through screens, where metals, bones, crockery, etc., are separated from the fertilizer filler proper. This filler is then cooled and bagged and is then ready for shipment. The tailings from the screens go on the dumps. There is left then only the water which has been separated from the grease; this is evaporated to the consistency of a thick syrup. and as much of this syrup as can be used is mixed with some of the solids before drying. This admixture with the evaporated stick produced a better grade of fertilizer filler than that which comes from the dryers without treatment.
 The economic uses of furnace slag have been greatly developed within the last few years. Formerly this slag was carted away from the furnace and dis posed of in the most available place, as so much refuse material, hardly worth the cost of carting. It was considered an encumbrance of the smelting works, of no account except to fill up gullies and ravines, or to be thrown into the sea. if such disposition could be made of it. Within very recent years it was estimated that the cost of removing this waste slag from the furnaces of Eng land was no less than $2,500,000 annual 1 ly The amount of slag made by the iron furnaces of Great Britain is cer- tainly immense. A considerable portion of this waste is now put to some profit able use as substitute for artificial porphyry in the construction of build ings for street pavements. Paving
 
 of Metz, Brussels and Paris of a quail ity sufficiently durable to stand heavy traffic.
 "A very important innovation in the metallurigcal industry in Germany is the utilizing of the waste gases of blast furnaces for working gas engines. That the waste gases can now be made ser viceable in their entire heating capacity by rational burning in gas engines, is one of the most important steps that have been recently made in science in it's adaptations to practical technics. What this improvement means, eco nomically, is seen by theoretic calcu- lation according to which this use yields a profit of $1.25 per ton of pig-iron pro- duction, which means for Germany alone, where the utilization of these waste gases is made gain Cf over $10,- GOO, ,00O0 on her entire wrought-iron pro- duction.
 Gas machines for utilizing these gases were introduced into Germany about 1898. Good results were reported from all quarters, which lead to the be- lief that this is material advance in the development of an important gas machine industry.
 Nearly all of the formerly waste prod ucts of lumber and timber are now turned to some utility and some of the new products thus formed are of con- siderable value Of this latter may be mentioned sawdust. which was former ly considered an absolute waste ma- terial, and was allowed to float down the stream or was thrown into heap where it could be most conveniently disposed of. French cabinetmakers have found a way of preparing this ma teraI which gives it value far above that of solid timber by process that has been in vogue for at least 25 or 30 years, combining the use of the hy- draulic press and the application of in tense heat. By this process the parti- cles of sawdust are formed into a solid mass capable of being moulded into any shape and of receiving brilliant pol ish, and possessing a durability and a beauty of appearance not found in ebony, rosewood, or mahogany. This product is known as 'bois durci.' Arti- ficial woodwork, therefore, seems to have promising future. Alum, glue and sawdust, kneaded with boiling wa ter into a dough and pressed into