96 
Eeport on the Miscellaneous Implemenis 
Such objections as might be takeu to the use of the electric 
spark, with its attendant battery and coil, for the ignition of the 
charge have been reduced, as far as possible, by the use of appa- 
ratus of the simplest type. The battery can be charged by 
any man of ordinary intelligence, while the terminals between 
which the spark passes are readily accessible and easily cleaned. 
Abrake trial of this engine was made by the Society's engineer, 
the consumption of petroleum being, meanwhile, determined by 
direct measurement. The speed of the engine and the needle 
of the spring balance were observed every five minutes. The 
petroleum was carefully measured by noting the height of the 
oil in the supply reservoir at the time that the engine started, 
and weighing back, after the run, the quantity of oil required to 
bring the new oil-level back to its original place. 
The engine ran rather irregularly, the speed varying, within 
very short periods of lime, from 150 to 180 revolutions per 
minute, while the explosive mixture occasionally missed fire. 
The exhaust-pipe from the cylinder was hot enough to char wood, 
but the products of combustion finally discharged into the air 
did not exhibit a temperature of more than 100°. The heat 
disappearing between the cylinder and exit pipe was used in 
raising the temperature of the heating-chamber. A piece of 
white paper held over the mouth of the exhaust-pipe was spat- 
tered with spray of petroleum in a manner to show that some 
oil escaped unconsumed. 
Results of Trial. 
Duration of trial 2 hours 
Mean numlier of revolutions per minute .... 165'5 
Mean effective load on bralce wheel .... 56'33 lbs. 
Effective diameter of brake wheel 5 feet 
Brake-horse-power ........ 4'48 
Petroleum consumed in 2 hours ..... 15'5 lbs. 
Petroleum consumed per brake H.P. per hour , . 1'73 lbs. 
The price of petroleum being calculated at Q\d. per gallon, 
the above represents a cost of, say, l\cl. per horse-power per 
hour. A steam engine of the same size would not consume less 
than 7 lbs. of coal per brake-horse-power per hour, which, at 
15s. per ton, would be, say, per brake-horse-power per hour. 
The Middlings Purifier (Art. 3885), exhibited by Messrs. 
WJutmore cfc Bimjon, of Wickham Market, is a new apparatus 
invented by Mr. Emil Weis. One of the most important 
machines made use of in connection with roller-milling, now in 
such common use, is the ]\Iiddling8 Purifier. By its means, the 
semolinas, which it is the object of gradual reduction to produce, 
are freed from the small particles mixed up with them, and are 
