Lamp Pump. 
135 
Another lever controls the backward motion of the carriage, 
which is 250 ft. a minute, and both movements are driven by 
an arrangement of friction gear. The carriage moves by means 
of two wrought steel pinions with machine cut teeth working 
into corresponding racks under each main side girder. The 
rate of cutting is exceptionally high, as much as 100 superficial 
feet of elm being dealt with in a minute, and the even running 
of the saw and. the firmness with which the log is held allow 
an exceptional smoothness of cut. The saws are thinner than 
those used in vertical log frames, and thus the waste of wood 
is slight, while the simplicity of control effects economy of 
labour. 
Article 4124 . — The Lamp Pump Syndicate, Ltd., 12, Carey 
Street, Westminster, S.W. “ Pump manufactured by the Pulso- 
meter Engineering Company, automatic vacuum lift and force 
for farm and other purposes^ with lamp and boiler complete.” 
Price 35Z. — This machine is direct driven by a single-acting 
condensing engine, and for lifts of less than 50 ft. it is worked 
by vacuum only, produced by condensing steam at atmospheric 
pressure ; for lifts exceeding 50 ft. the power of the pump 
may be increased by using steam above atmospheric i)ressure. 
Steam is supplied by a small boiler heated by an ordinary 
paraffin furnace lamp. The construction of the apparatus is 
shown by the sectional elevation (Fig. 4). The engine, main 
pump, and air pump are of gunmetal throughout, the body of 
the condenser is of cast iron, and the condensing surface is 
provided by the suction pipe of the pump which passes through 
the body of the condenser. The upjjer end of the piston rod 
is provided with a T handle, and as soon as the water in the 
boiler retiches a temperature of 212“ the pump is started by 
hand for a few strokes until a vacuum is formed, when the 
action of the machine is entirely automatic. The diagram 
shows the piston at the bottom of the stroke, and the control 
valve (a) is in such a position that steam enters through the 
port (b) and passes through the pipe (d) to the under side of 
the piston. The upper side of the piston is under vacuum, 
being in communication with the condenser (f) through the 
port (C) and the pipe (K), and the piston commences its up 
stroke. The valve (a) is held in position by vacuum on the 
under side of the working piston at its lower end, this side 
being in communication through the pipe (e) with the upper 
end of the engine cylinder, which has alreadj^ been shown to 
be open to the condenser. When the main piston reaches the 
top of its stroke, it opens the pipe (E) to the steam on its under 
side, and the vacuum below the working piston of the valve 
(a) is destroyed, and as the upper end of 'the valve is open to 
the condenser the valve rises, closing the steam port (B), cutting 
