Daily union and American. [volume] (Nashville, Tenn.) 1865-1866, 1866-10-19
aIai0u aud smerifau,
The NicOlson Pavement.
HOW Il Has Been laid. and How IL
should be Laid in ChienEo.
a LETTER FROM MIR. NICoLsoN.

SlIERNAN HOUSE, CHICAGO, Oct. Is. 1866.
Messrs. GOODWIN d LARNED: GeHaemea-
During the last four days have visited sew
eral streets in the city now being paved with
the Nlcolson pavement As the inventor
and patentee Of the pavement, feel that I
nave the right TO express my opinion as 10
the construction and the materials used in
forming said pavement, both for the credit
Of my invention and the protection Of pro-
perry owners who are required TO pay for
the same and l address you on the subject
as my general agents for the pavement in all
the Western States with the hope that you
may be able 10 effect such changes as 10
cause contractors to be more particular, and
give to the public a pavement that shall be
better and more enduring than many Of
those which have lately been constructed in
this city.
On the streets where the work is now in
progress, / find that the flooring is too open
between the boards. The joints should be
close, 50 az 70 add strength and solidity to
the pavement and to prevent moisture from
the earth beneath coming to the blocks.
A better method Of tarring the boards Of
the hoorIng, which has been practiced in
other places, Is TO dip the floor boards in hot
tar, previously prepared in long shallow
iron tanks, where il is constantly kept hot
for that purpose. This method, while il ef-
iects more perfect covering of the entire
board sides and ends with tar, is at the same
time (by the prevention Of waste) found TO
be more economical, with respect to the
amount Of tar consumed. It has also been
found useful 10 dip the lower half Of the
blocks in hot tar just previously to their be-
ing laid in position.
The blocks in the lines or rows Of blocksI
found 20 be Of irregular dimensions, ranging
from p TO B inches in thickness in the
same row; the effect Of which is, 10 make
the channels between the the rows of an I'M
equal width, they being in some places ] z
inches wideand inotherplaces aboutone inch
wide. This causes unequal and irregular
surface wear BIZ travel. The blocks in each
row should be Of equal thickness, and so as
sorted and laid as 70 cause the channels be-
tween the rows Of blocks 10 be of the uni
form width Of not more one than inch. The
strips between the rows of blocks should be
little less than an inch thick, so as to fll
the channels made as above stated, and the
whole should be firmly end compactly forced
getheI.
i found on measuring some Of the blocks
that they were from sixteen to twenty inches
long on the upper surface, IN consequence
Of which they cannot adapt themselves per-
fectly 70 the curve Of the streets, and the
bearing Of the block being upon the centre,
gives a rocking motion 10 the block as car
riages pass over one or the other end Of It.
The effect Ct this would be the loosening of
the filling and the admission Of water and
frost 90 an injurious extent. Such blocks
should be divided into two, so as that each
block may receive better and more equal
bearing upon the floor. The blocks should
not be more than ten inches in length.
found that the gravel used for the filling
between the rows Of blocks was composed in
great degree Of large stones, many Of which
were one and half to two inches in diane
tea. Such stones are not suitable for the
filling, and becoming lodged in the chan
nels, prevent them from being properly filled.
The proper size Of gravel for Cling should
not be less than a quarter of an inch, nor
more than three-quarters Of an inch in di-
ameter. Screens may be easily constructed
that win exclude all gravel larger or small
er than the sizes nave named. The gravel,
when used, should be perfectly dry, and it
is preferable Il should be heated and the
channels between the blocks filled TO the
surface Of the pavement, and the tar, having
been boiled to a proper consistency, should
be poured in its hot state, thoroughly into
and amongst the hot dry gravel, very soon
after which, the gravel should be rammed
with the usual instruments. Then the
whole surface Of the pavement should be
well covered with hot tar, and covering Of
sand or small gravel two inches thick should
be Immediately spread over the whole.
Not less than two and two-thirds of a gal
Ion Of tar should be used to a square yard
Of pavement.
When stress are paved with the Nicol-
son pavement Immediately after being filled
to grade with soft, yielding filling material,
there is, Of course, some liability for the
pavement to settle unequally, which may, to
some extent, prove injurious. But if It is
properly laid, Il will, even in such cases, do
good service for many years, as is shown by
the pavement laid on South Clark street,
which has lasted eight years under the in
cessant travel Of that street. without material
repairs. That pavement was laid immed
ately after the filling of the street to grade.
and the irregular shapes and curves into
which the rows Of blocks had been thrown
in consequence Of the settling Of the street
without destroying the integrity Of the pave
ment, is a testimony at once 20 the excel
lence Of the pavement and Of the construc-
ton. There is no other pavement which
can be laid upon such newly-filled streets
which will be found TO stand so well as the
Nicolson. Il would be desirable in such
cases to increase the thickness of the floor
ing upon which the pavement is laid.
think it would be for the advantage Of
the property owners, as well as of the pave
ment, II some trustworthy and competent
person, familiar with the proper mode Of
constructing the pavement, should be APP
pointed inspector Of all the Nicolson pave
ment laid or repaired in this city, so as 10
insure the faithful and skillful execution Of
the work. Il would prove a large saving to
the taxpayers in the end.
If the materials used in the pavement are
good, and the foundation to receive the
pavement firm and solid, and the construc-
zion Of the pavement carefully and skilfully
attended, 90, feel confident that the public
may rely on its continuance without mate-
rial repairs under the heaviest travel upon
your streets for twelve or fifteen years
Respectfully.