62 ANNUAL OF SCIENTIFIC DISCOVERY. 



in working a hoisting apparatus in a London warehouse, gave the 

 following results. The engine had a 6-inch cylinder and 10-inch 

 stroke, and was equal to 3 horse-power, the boiler being equal to 

 only 2 horse-power. The rate -of working was 150 strokes per 

 minute, and the trial started with 60 pounds steam, when 1,250 

 pounds were lifted 50 feet high in 30 seconds. Eight lifts were then 

 made with the same weight, occupying with the loweriugs 6 min- 

 utes. During the lifting the steam fell to 40 pounds, but in 2 min- 

 utes rose again to 50 pounds ; four lifts and lowerings were then 

 made in 4 minutes, the steam after each lift falling 3 pounds, but 

 recovering itself in 30 seconds ; these 30 seconds were occupied by 

 the lowering, during which steam is not used. The amount of 

 gas consumed was 50 feet in 15 minutes. 



In another of these boilers, 4 gallons of water were evaporated 

 in 30 minutes, with 75 feet of gas consumed ; the same quantity 

 was evaporated in 26 minutes, with 50 feet of gas consumed ; 16 

 gallons in 86 minutes, with 200 feet of gas consumed ; and 8 gal- 

 lons in 43 minutes, with 100 feet of gas consumed. The pressure 

 gauge ranged from 55 to 65 pounds, and the temperature of the 

 heat passing out of the chimney was 300 degrees. Mech. Mag., 1867. 



BOILER INCRUSTATIONS. 



Friedrich, a German chemist, has published a method of pre- 

 venting boiler incrustations, by putting pyroligneous acid into the 

 water of the boiler until it faintly reddens litmus paper. This 

 converts the carbonate of lime into the acetate, a much more sol- 

 uble salt. More acid must be added as often as the boiler is fed, 

 as the excess will always be distilled off with the steam. This, 

 however, is capable of application only when the carbonate is the 

 only lime salt present in the water; and to prevent the formation 

 of crust in this case, common pyroligneous acid is probably as 

 cheap as any boiler composition. 



A NEW AMALGAMATOR. 



Recent trials with a new amalgamator and desulphurizer have 

 been made upon some of the most refractory ores, with results 

 that promise a great revolution in gold and silver mining. 



The powdered quartz, mercury, and sufficient water are placed 

 in a wrought-iron cylinder, which is then closed air-tight and made 

 to revolve slowly over a fire on a movable truck until the steam 

 gauge indicates 70 or 120 pounds steam, according to the nature 

 of the quartz. If the quartz does not contain much refractory ore, 

 70 pounds of steam are sufficient ; if it contain much, 120 pounds 

 of steam are necessary to thoroughly desulphurize and liberate 

 the gold and silver. As soon as the required amount of steam is 

 attained, the fire is withdrawn and the cylinder is kept revolving 

 until cool. It is then opened and emptied, and is ready to repeat 

 the operation. The machine will treat from 1,500 to 2,000 pounds 

 of quartz at a time, inside of three hours, at very little expense. 



It is claimed for the above process, that the steam not only 

 desulphurizes but drives the heated mercury through the quartz in 



