Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1892-09-04

especially familiar in Pittsburg. Already
about 45 miles of the streets of that city
have been paved with the substantial blue
have their own way many more miles Of
Pittsburg streets will be paved in the same
way within few years
The blue stone blocks used for paving in
Pittsburg come from deposit near the
Packsaddle, an outcrop on one of the spurs
of the Allegheny Mountains. Another de-
posit of the same quality of stone is found
above Connellsville on the Baltimore and
Ohio road, an outcrop from another spur OF
the same mountains, but the Ligonier blue
stones, as all the deposits are called, seem
to be native in the Ligonier Valley
Seven Millions of the Blocks.
Last year there were taken from the Lig-
onier quarries and transferred to the streets
of Pittsburg just 1000, 600 of the blue stone
blocks Two years ago about 3,000,0 900 of
the blocks were transferred in the same
! way, and this year it is estimated that
5000, 900 more of the Blocks will be sent to
Pittsburg for paving purposes. The blocks
were first introduced in Pittsburg five
years ago. They are almost imperishable,
and are said to be almost as hard as ada
mant
The great quarry was originally opened
for street paving stone. but within two
years it has been supplying a little of every
thing that is made from stone. Plans for
stone houses are now sent to the quarry
here, and the structure In sections is
shipped away, every piece numbered and
ready to be put together, thus recalling the
building of Solomon's Temple of old
The building stones as we'll as the paving
blocks are chopped out Of a mammoth rock,
the face of which is now exposed to depth
of IS feet and extending along the ridge for
nearly mile. The rock is first blasted by
drilling with compressed air. Glycerine is
poured into the holes and exploded as an
oil well is shot. One blast as rule tears
out enough stone to build a house or Two,
and exhausts an ordinary appropriation for
street paving block.
Sawed With the Sofsest Iron.
The building stones are carried down on
an. incline from the quarry to the sawmill,
where they are sawed out according to plans
and specifications Saving stone is not
much of a novelty. Many quarries saw out
building stones, and some Of them use dia-
mond pointed saws of rare value and great
cost But saving Ligonier block stone,
the hardest in the market, with the softest
iron made, is an innovation and can be seen
at no other quarry in this country The
saws are made especially for the purpose
and are made especially soft They are
ordinary iron bars about 10 feet long, 3
inches wide and 3-16 of an inch thick. The
rough stones are placed on trucks and
| rolled in under the saws that are set in sub
| stantial frames. The saws are operated jus
| as the saws in any mill are operated. Un-
der the saw is pool of water into which a
certain amount of crushed steel is thrown
The steam power operating the saws pumps
the water and crushed steel into the saws
track and the soft iron blades with the as
| sistance of the water and steel, carves
through the rough stone like cheese knife
would wade through roll of fresh butter.
There are three saws in the mill here, and
two men are required to operate each of
! them. A branch of the Ligonier Valley
Railroad extends up to the door of the mill
and the stones as sawed are shifted from the
trucks to the cars Besides building stone,
flags for street crossings are sawed out, and
just near the saws is a huge polishing
machine, where a patent-leather shine is
put on any of the stones desired.
None OF the Stone Cots Away
Alex. McConce, superintendent of the
quarries, here told me yesterday that for
the past five years an average of 20 cars q