New-York tribune., 1896-05-24

in his visit. The great gray rocks that are
shivering into fragments under the dynamite
cartridge could tell strange stories of other
MECHANISM OF THE ENGINE.
1t +. likely though. that the greater interest
will be centred upon things modern and the
most modern thing is the air plant. Last fall
the dancing pavilion adjoining the old Jerome
Park clubhouse moved ncrthward from
the greater emnence to summer Hill. Stoutly
built IL makes an ideal power house, with It's
great floor space and high. wide windows that
let In plenty OF light and air After the struct-
ure had been firmly established uron lts he%
foundation miniature lake was constructed
upon one side OF IT. This was TO furnish the
water supply for the boilers Within the house
a GOO horse power compound Corliss engine was
placed with steam condenser apparatus at
tached The steam after use. passes into the
condenser and emerges through the escape-pIpe
into the lake water, to be used over again
This is a familiar enough process The ar
cylinder is the curious part or II all 10 the
layman.
Just In line with the main cylinder of the en-,
cine and about three feet from the cylinder mead
there is another cylinder of peculiar construc-
ton The piston rod OF the engine continues
through the steam cylinder ana INTO anu
through the air cylinder, The rod pass pass'nS nS
through the air cylinder is hollow tube OF
steel. and as II works inward draws the air lnlo
the cylinder by suction. So strong IS the SUCTION
that considerable muscular eNeruoh ~ heeteu
prevent one mana DtlnB uTdNl lH'p II va '''N
return stroke. The air once INSIDE; Passes
through prepared valves into the cylinder itself
and 10 then forced into a feeder eight lncheS III
diameter and from that point Is carried 10 a
storage tank just outside the building. rms
tank. which IS equipped with a safety paiNe 10
regulate and control the pressure. mas o" CUBIC
feet Of capacity. The air is compressed to sixty
five pounds to the cubic inch. although this can
be Increased as occasion requires.
From the storage tank an S-nch main
leads off toward the Aqueduct; which lies west
hAtt
hundreds Of feet from the tank this main pipe
is reduced TO four inches in diameter Pipes
two inches and one and one-haf inches In diam
eter run direct from the smaller main to the
drills. the pumps and the derricks The drills
are OF the sort that excavation work on Man
haitian Island has made familiar. for their noisy
keeping the trenches for the great core wall
clear OF water This at times is difficult task.
for springs abound and at the very beginning or
the work was struck at the depth OF nearly
nftv feet below the level of the Boston Road. that
made a regular running brook at the bottom OF
'"e THE AIR HEATED.
The derricks are powerful affairs Of the swing
Ing boom variety. with engines attached for
moving heavy stone, whether for the wall or in
the excavation work. About twenty drills an
equal number Of derricks and number of pumps
draw their power from the air plant. and the
distance covered from the power-house Is nearly
half mile. Il has been said that eXtraneous
aid must be called into play TO restore the drv-
ing efficiency OF the air after 1t has travelled
certain distance. Like steam, II loses Its power
This difficulty Is overcome by simple process.
Restorative plants are prepared at given dis-
tances in the shape of extra tanks carrying
drebox underneath The air is driven into these
tanks at high pressure and reheated. Its buoy
ancy restored IT passes out through another
main and continues on its way to drill. pump or
derrick as may be desired. Such is the problem
for saving of labor and money that Mr. Nc
Donald and bis engineers have been slowly but