The sun. [volume] (New York [N.Y.]) 1833-1916, 1861-02-18

Britain a. Seatop's rail. The rail re.ts an q
stradde, triangular timber on longitudinal
sleeper, which has one corner up and the a.
side do~n,in the ppsiticn Il ridge board on the
roof Of country horsc. Tho sieep.rs srs
formed by splitting sqssrs stich diogonsiiy.
each half forming SLEEPER and ssch sleopsr
having greater bearing on the ballast tina.
| would any side Of the square stick from which
II was cut. The A rail has considerable yerti-
cal stiffness a. well ~ much side stiffness, bstA
Of which are necessary for street nel
and 1t presents only q narrow tread %
tho surface upon which horses will not
Il clip. One II tho chief disadvaatages u
. rail which Is ss wide a. the timber on which
II rests, s, that the continuity Of the paving b
bioker--it stops square and short at the ti.-
br. At other parts, the stones break joints.
snd the pressure on them Is partially distriks-
ted among several sf them, bat whsn thsy
sIop st a SOU re line they arc more likely 70 -
pounded down. E-peciaily fs this the case q
ihe sid. of q rail, for however slightly II pro
jccts upward, It will catch and hold wheels Il
vehicles which sJprosch it at an acute anglia
50 that tf'c weakest part of the pavement is
most travelled on and most hsNsrcrcd down.
Tho rail with its fargef A timber forms .
support for he stoBrs, which ars bevollod 70
6t them. SO the weight coming ON ono Of tAs
stones close to tho rail is distrihuted to ths
whole whie and long bearing susfacs Of The
timber, snd the pavement 10 strongest whss
most strength Is required.
In MAKING FRE-BRiCKs, tho clay, sf.sr bs-
ing dug ont, Is exposed TO the atmcsp sphere fsr
sore days, sometimes for wcsks beiore IL II
removed to the mill, where il is ground int Q
coarse powder with a mi Sture VI one-sixth ~
old burnt clay. Tho common mill used fw
grinding Il Is simply two largo stones or cast
iron wheels set on an edge and rcvolved BY .
shAft in suitable bearings, In trough int
which the clay 10 fed. The trough o. bed
plate in which the clay Is ground Is Of cast iron,
and ss the clay is reduced to proper fineness II
falls into rcco ptaclc, from which IL is carried
away hy cOnycyCr similar TO that In a grist-
mill, and IL then deposited in common pug
mill whnrc IL L. xed with water aud thoroughly
sneaded into proper condition to render IL 1T
for moulding. These bricks are moulded Ike
building bricks, and are afterwards exposed 70
ict in wsrm apartment, where they are tho
roughly dried preparatory to bciug bursed.
For this purpOse they are placed in kilns smi-
lar in form anil construction 90 those employee
for baking pot,eiy-warr. Here they arc sub
jcctcd to very high heat, and IL generally
tskes constant dring for i've days before fiftssa
thousand bricks can I've burned in kiln 70 artssa
fest In diameter and ten feet high The firing
Of such bricks must be conducted with great
Care. They arc 20 laid On their edges, ess
|rabovc another, and in rows, that spaces of
about half sn inch are left between the linea-
These spaces answer the purpose Of minnie
hues the hams and hot gases pass thrsvah
them up to the chimney, which 10 sitsateA at
the back end Of the kiln.