Amster's Recording Dynamometer (Fig. 4) consists of two arms, one of which is keyed on the driving-shaft and the other on the following-shaft, the two shafts be ing in line end to end. The arms are connected by spiral springs, the compression of which measures the effort transmitted, and to avoid violent vibrations a dash-pot is fitted inside the coils of one of the springs. To record the eompression of the springs the arm of t he dynamometer carries a set of three drums, from the lint of which a roll of paper is gradually unwound as he dynamometer revolves, and passing over the second drum is reeloiled on the third. A pencil connected with one of the t W41 spiral springs marks the paper as it passes over the second drum. The method adopted for working the drums is peenliar. A weighted lever vi brates on its renter through a limited arc as the dvna revolve., thus netitathig n ratchet, which in tarn moves the 111'1111N fOrW21111 stop by step; this sim ple device has 110(.11 found to act monist satisfactorily up speed 1:i0 ITVI)! ill ions per minute.
Ejector : see larve,t ing Machines, Grain and PN ErMA TIC. An apparatus for removing, sewage 'used in the so-called system. SPW:12.1e from a given district is flintily collected into one pipe, shown at the left Fig. I, and flows into the ejector at the bottom..
When the ejector is filled, an automatic action is established which admits compressed air, brought to the ejector from a central compressing station, which may be. as at Eastbourne, England, three miles away. The compressed air acts on the contained sewage in the air-tight ejector with the requisite pressure, driving it out of the ejector into the sewage-main, no matter how high the latter may be above the ejector level. The sewage being ejected, the action of the automatic gearing is reversed, which cuts off the supply of compressed air, and permits the air in the ejector to escape into the sewers, to aid in their ventilation. The sewage then
flows in again, and the action is re peated as often as is necessary. depend ing entirely upon the volume of flow.
It will be observed that the com pressed air is not admitted until the ejector is full, and the air is not al lowed to exhaust until the ejector is emptied down to the discharging level. In consequence of these actions the sewage is got rid of just as fast as it is produced.
The air is compressed in a central station by the use of steam-boilers or gas-engines, the air, after compression, being stored in iron receivers or in the air-mains themselves, if of sufficient length. It is carried to each ejector in small iron pipes.
By the use of the pneumatic ejec tor, basements can be drained even when far below the main sewer.
It may also be used to raise water to tanks on the tops of large buildings, for elevator and domestic supplies.
With regard to the economy of pumping with compressed air, the following table gives the percentage of useful effect which, it is claimed, can be obtained in the ejectors for various heads : It is also stated that, from actual diagrams taken from a pair of small steam-cylinders 101 in. in diameter, compressing air in a pair of 14-in. cylinders to a pressure of 24 lbs. to the sq. in.. which corresponds to a head of 55 ft., 50 per cent of the total indicated horse-power exerted in the steum-cylmder has been got in actual work in the ejector.
Electric Coal-Mining: see Coal-Mining Machines. Electric Crane : see Cranes. Electric Elevator: see Elevators. Electric Locomotive: see Electric Motors. Electric Production of Aluminium : see Aluminium. Electric Pump : see Pumps. Reciprocating. Electric Railway : see Railways, Electric. Electric Regulator : see Car-Heating. Elec tric see Welding, Electric. Electric Rock Drill: see Drills, Rock. Electric Sole Sorter: see Leather Working-Machines.
Elevators : see Mills, Silver and Ore-Dressing Machinery.