New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1902-06-01
GETTING RID OF ROCK.
WHAT HAS TO BE DONE on MANY
BUILDING SITES IN THIS CITY
WORK OF POWER DRILL.

\
Can real estate in the rocky portions OF the city
| be fitted for the reception Of buildings at less
cost than land numbered with huge masses OIL
rock? In the opinion OF those most familiar with
| the problem it certainly cannot
The question was asked for the purpose OF ascer-
tanning the value OF the stone removed in excavat-
| ing as A marketable commodity. and Its erect III
this relation upon the price Of real estate The
| person buying a rocky building site with the as"
reaping profit from the stone thereon VIII 'Ii'u
himself in the position of that Oriental potentate
| who was similarly inspired in the elephant line
The question is of disposal entirely ana
! when a contract can be obtained for cellar build
| ing retaining walls or filling In within a reason"
able distance of the be prepared operations
may he conducted on Il most economical scale
This cannot always be done. however anu "lieA
| g cannot the contractor obliged 10 avail NM
self of the services of the owners OF the du'hihs
scows who receive the dirt and stone at " GEMS
a wagon load and deposit it three miies-ilole VI
Iess-of the coast. Though forbidden by law 10
DUNN within less than three miles of the coast
they are said to exceed this when dufnp'is
bv night. In the event OF there being a ue'iai'u
for stone or dirt for the construction OF break
water along the Jersey coast or for purposes Vi
filling in the many islands about the haFooi'
as is often case then the contractor Is
nate enough dispose of his material free OF a' d
slight 80
The cost of removing cubic yard OF material
depends entirely upon the conditions present III
each particular case. is stated as ranging De
tween minimum of 81 70 and $ or 80 maximum
If the lot to be excavated is an isolated one con-
ditions are at their best and the contractor is only
limited by the length of his drills and the strength
Of his powder but where he is obliged To prepare
n lot building which is already SURROUNDED oS
structures then he must exercise his pest JudSneii'
TO get the most OF his means without endanger-
ing his profit by damaging the surrounding Dulio-
irps One extensive but effective method OF pre-
venting damage adjacent structures by concus-
sons from the blasting Is the following; The ouiId
ING 70 he protected is separated from the rock mass
TO be operated by a row of holes drilled 10 the
dentb of the intended excavation. about three
inches apart This acts as cushion against the
blasting and, slight ii would SEEM II Is cer'i
that disaster would follow were 1t neglected
Another source of danger to the adjoining prop
or,,. oyrers is the careless workman the man who
never nuts enough protecting logs over his blast
with the result that powders OF varying uliileH-
sions crash through the walls or the ADJOINING
house He is even more dangerous. but perhaps
not as careless the man who warns dyhahlte
over an omen fire. for former is limited only oy
opportunity while the latter seldom repeats MS
carelessness As the blasts approach the ouldlhs
they are lessened in strength. and the last rev
slices of rock are generally broken OFF by wedges
driven in the drill holes or by very shsh' chaise'
O dynamite
The law compelling property owners 10 CONFORM
to n certain street grade in building IN the irregular
localities north OF the city has proved wise one
and the perfect streets OF the Harlem OF TO-DAY
bear no trace their former ruggedness- Inc lacA
of such law permitted dwellers In similar io
calIties in San Francisco to construct their dom
Giles at any desired convenient elevation anu
the result is in some cases most starting, ing. ,5
changes have been wrought in the OUTLYING portions
Of the city in the aSt mention OF the power rock
drill through whose agency these results nave pei,
recent invention that has enabled the contractor
10 keep pace WITH the hdmn rS' the cI dwelling
Almost every one is familiar with the buzzips Of
this three legged steel cicada. but few probably
stop to cHnsa1 tb MS CONTRACTOR Those who watched
the excavations in the neighborhood or thirty
changes We're ~ marked from day day there
nothing remarkabe in the operation of the score
of putting hammerng noisy tripods From 3 a point
to be preferred but when derrick PICKED 1 up a
on the street level fifty feet above could not
but that expedition was the great desidera tum
hand method that the former takes its true place
the Century. The blow struck by, brawny ham
norman welding an eght-pound hammer wn nin
under the most favorable conditions that two
penetrate Gl to depth of than feet in the
ordinary raprock Of this vicinity ! IN ten hours
dtions and in the same time will drili nine holes |
of OF moving and setting the drill that number Of
o e Of reaeh Of he r n small
tons. An inquiry into the origin OF the power |
records that drop drilling mach9e was uss5
blows sink hole one and half inches deep and
a hands breadth wide and long" and o from the
same country comes the report that in 1903 a ma |
chine said to be quicker than miner was made |
at Sulzburg. Richard Trevittick distinguished |
English engineer, is said to have suggested rock
drilling by machinery. but the power rock drill Is |
distinctly American invention. as the first !
patent for persuasive rock drill was issued TO |
s. year Joseph Of
patented rock drill. the first one constructed in
which the drilling tool directly attached to the |
engine, or. in other words. was an elongauon OF
the piston rod This is the principle on which the
modern drill is constructed. and it has been |
brought to its present high state of perfection by
improvements
Sergeant and others. The first practical demon |
stration OF its value in excavating was IN the con-
struction OF the famous Hoosac Tunnel In 1865 and
1856 but Its use among contractors was not gen.
eral until ten of fifteen years later steam is the