Side
af
764
Forrige
Næste
107 OF ENGINEERING- FORMULÆ.
Tunnels,
From actual Practice in Brickwork.
! Formation of Extreme
j Strata. height.
treme width. Thick- ness of lining at Crown.
ft. in. ft. in.
17 0 1 2
20 0 1 6
37 6 2 6
21 0 1 6
27 0 1 io;
30 0 1 10*
30 0 2 3
36 0 2 3
35 6 1 2
ft in.
Canal ... . Various.. .. 16 2
Thames Tuunel .. London Clay . 21 6
.. .. 22 3
Railway, N. gauge Chalk .. .. 26 6
Various.. . 27 6
Shale .. .. 30 0
„ { Lower Green Sand .. .. | 30 6
„ B- » Freestone .. 36 0
Canal .. .. | Chalk and Fuller’s Earth ^39 0
Table of Wells on Barrel-drains.
Quantities in One Lineal Yard.
Diam. in feet. Con- tents in gallons. | Brick thick. 1 Brick thick.
Cube yards. Brick- work. No. of bricks. Cube yards. Brick- work. 1 No. of bricks.
Dry. In mortar. j Dry. Mortar.
li 33 •25 114 93 -59 j 270 222
2 58 *31 144 J23 •12 336 276
3 131 •44 204 171 •98 j 462 378
4 235 57 267 219 1-24 582 477
5 368 ■1 330 270 1-5 702 576
6 536 •83 390 321 1-77 828 678
7 723 •96 450 369 2’03 948 780
8 942 1-09 510 420 2-28 1074 876
9 1193 1’22 573 468 2’55 1194 978
10 1472 1-36 636 522 2-81 1314 1080