to graduate the table for each separate degree of temperature, the columns in the table show the weights for every 8 degrees Reaumur, which is quite sufficient:  namely, from 24 deg. to 17 deg., from 16 deg. to 9 deg., and so on, down to -24 deg.; the equivalent Fahrenheit range being from 86 deg. down to -22 deg.  Suppose the filling of a tender tank draws off a height of 27 in. from the distributing tank, at a temperature of say -20 deg.  R., these figures are shown by the table to correspond with 200.61 poods = 7,245 lb., or 3.23 tons, of petroleum.  This arrangement does very well in practice; both the quantity and the temperature are entered on the driver’s fuel bill at the time of his taking in his supply.

Engines.—­The engines used in the trials were built by Borsig, of Berlin, Schneider, of Creusot, and the Russian Mechanical and Mining Company, of St. Petersburg.  Their main dimensions and weights were about the same, as follows, all of them having six wheels coupled, and 36 tons adhesive weight; as originally constructed they had ordinary fire boxes for burning anthracite or wood; cylinders 18-1/8 in. diameter and 24 in. stroke; slide valves, outside lap 1-1/16 in., inside lap 3/32 in., maximum travel, 4-9/16 in.; Stephenson link motion; boiler pressure, 120 lb. per square inch; six wheels, all coupled, 4 ft. 3 in. in diameter; distance between centers of leading and middle wheels, 6 ft. 2-3/4 in.; between middle and trailing, 4 ft. 9-1/4 in.; total length of wheel base, 11 ft.; weight empty, on leading wheels, 12.041 tons; middle, 10.782 tons; trailing, 10.685 tons; total weight, 33.508 tons empty; weight in running order, on leading wheels, 12.563 tons; middle, 11.885 tons; trailing 12.790 tons; total weight, 37.238 tons in running order.  Tubes number 151; outside diameter, 2-1/8 in.; length between tube plates, 13 ft. 10-1/8 in.; outside heating surface, 1,166 square feet; fire box heating surface, 82 square feet; total heating surface, 1,248 square feet; fire grate area, 17 square feet; tractive power = 65 per cent. of boiler pressure x (cyl. diam.) squared x stroke / diameter of wheels = 0.65 x 120 x (18.125) squared x 24 / 51 = 5.383 tons.  Ratio of tractive power to adhesion weight = 5.383 / 37.238 = 1 / 6.9.

Tender.—­Contents:  water, 310 cubic feet, or 1,933 gallons, or 81/2 tons; anthracite, 600 poods, or 10 tons; or wood, 11/2 cubic sajene, or 514 cubic feet; weight empty, 13.477 tons; weight in running order, 28.665 tons; six wheels.

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Petroleum Refuse—­Comparative Trials with Petroleum, Anthracite, Bituminous Coal, and Wood, between Archeda and Tsaritsin on Grazi and Tsaritsin Railway, in Winter Time.