Name of Substance.

Specific Gravity.

Weight of a cub. ft. in lbs.

Air (atmospheric) ............

.0012

Alabaster. See Gypsum...

Asphalte (gritted) .. ..

2.496 Hu.

156.00

Basalt............

from

3.00

187.50

to

2.478

154.87

„ (Fairhead) .. ..

2.95 K.

184.37

„ (Derbyshire) .. ..

2.921 W.

182.56

„ (Giant's Causeway)

2.90 K.

181.25

" " ,

2.864 Br.

179.00

„ (Rowley rag) ..

2.478 K.

154.87

Beeswax (yellow) ..

.965

60.31

Bismuth (cast)................

9.822

613.87

Bitumen, of Judea ..

1.104

69.00

Brass (wire drawn) .. ..

8.544

534.00

„ (plate) ...............

8.441 W.

527.56

„ (cast) ........................

8.100 P.

506.25

Brick (common).. .

from

1.557

97.31

to

2.000

125.00

" (red).................

2.168 Re.

135.50

„ (pale red) .......... ..

2.085 Re.

130.31

" ..............................

1.857 Be.

116.06

„ (common London stock ............................

1.841 T.

115.06

Brick paving (English clinker....................

1.653 R.

103.31

Brick (Dutch clinker)

1.482 R.

92.62

„ (Welsh fire) .. ..

2.408 T.

150.50

Brickwork in mortar, about

110.00

Cement (Roman) and sand in equal parts .. ..

1.817 T.

113.56

Cement alone (cast) ..

1.600 R.

100.00

Chalk......

from

2.000 Hu.

125.00

to

2.657 Th.

166.06

,, (Cambridge clunch)..

2.657 W..

166.06

" (Dorking).....................

1.869 R.

116.81

Charcoal from birch ..

.542 K.

33.87

" from fir..........

.441 K.

27.56

„ from oak.....

.332 K.

20.75

„ from pine ..

.280 K.

17.50

Clay (potter's) .. .

from

1.800

112.50

to

2.085 K.

130.31

" (common)................

1.919 Be.

119.93

,, with gravel .............

2.560

160.00

„ slate. See Slate.

Coal (Kilkenny)..............

1.526 K

95.37

" (Glasgow splint).. ..

1.290 Th.

80.62

" (Cannel)....................

1.272 Th.

79.50

„ (Newcastle caking) ..

1.269 Th.

79.31

Coke ........

.744 K.

46.50

Concrete (lime)..................

2.080

130.

" (cement) ........

2.176

136.00

Copper (British sheet) ............

8.785 Ha.

549.06

Name of Substance.

Specific Gravity.

Weight of a cub. ft. in lbs.

Copper (British cast) .......

8.607 Ha.

537.93

Earth (common)

from

1.520

95.00

to

1.984

124.00

„ (loamy or strong) ..

2.016

126.00

„ (rammed) .. ..

1.584

99.00

„ (loose or sandy) ..

1.520

95.00

Firestone.............................

1.800

112.50

Flint...........

from

2.580

161.25

to

2.630 Th.

164.37

„ (black Cambridge)..

2.592 W.

162.00

Freestone. See Stone.

Glass, white flint .. ..

3.000

187.50

" plate......................

2.760

172.50

" crown.....................

2.520

157.50

Gold, pure cast ......................

19.361 Br.

1210.06

„ standard ............

17.724 Th.

1107.75

Granite .. ..

from

2.999

187.47

to

2.538 K.

158.62

„ (Guernsey) .. ..

2.960 Hu.

185.00

„ (Aberdeen grey) ..

2.664 R.

166.5

„ (Cornish) ..............

2.662 Re.

166.37

,, (ditto).....................

2.653 R.

165.81

„ (Aberdeen red) ..

2.613 R.

165.18

„ (Cornish) .......

2.624 T.

164.00

Gravel ..............................

1.749 P.

109.32

Gunpowder (solid) .. ..

1.745

109.06

„ (shaken)........

.922

57.62

Gutta-percha....................

.976 Hu.

61.00

Gypsum (plaster stone) ..

2.286 W.

142.87

India-rubber.......................

.968 Hu.

60.50

„ (vulcanized)

1.040 Hu.

65.00

Iron (bar) .. .. .

from

7.600

475.00

to

7.800 K.

487.50

„ hammered .. ..

7.763 M.

485.18

„ not hammered .......

7.600 M.

475.00

„ (cast) .. .. .

from

7.600

475.00

to

7.200 Th.

450.00

„ horizontal ditto ..

7.113 Re.

444.56

„ vertical castings .........

7.074 Re.

442.12

Ivory .................................

1.826 P.

114.12

Lead (milled)........................

11.407 Th.

712.93

,, (cast)............................

11.352 Br.

709.50

„ black. See Plumbago.

Lime, quick.....................

.843 Be.

52.68

Limestone. See Stone and Marble.

Loam. See Earth.

Marble .. .. .

from

2.840

177.50

to

2.580

161.25

„ Parian white ...

2.837 K.

177.31

„ veined white ....

2.726 Re.

170.37

No. XXI. - continued.

Name of Substance.

Specific Gravity.

Weight of a cub. ft.

in lbs.

Marble, Carrara white,..........

2.717 K.

169.81

" " blue .. ..

2.713 K.

169.56

" Italian black.. ..

2.712 K.

169.50

" Derbyshire entrochal

2.709 R.

169.31

" Saxon grey .. ..

2.700 K.

168.75

" Brabant black

2.697 lie.

168.56

" Derbyshire black ..

2.690 W.

168.12

" Namur black.. ..

2.682 R.

167.62

" Sienna yellow

2.677 K.

167.3l|

" Pallion brown figured ......................

2.586 R.

161.62

Marl...............................

from

1.600

100.00

to

2.870 Th.

179.37

Mercury (fluid).....................

13.568 Hr.

848.00

Mortar (new)..........................

1.760 Hu.

110.00

" of river sand 3 parts, of lime in paste

2 parts..........................

1.615 Ro.

100.93

Mortar, ditto, ditto, well beat together .. ..

1.893 Ro.

118.31

Mortar, of pit sand 3 parts, of lime in paste 2 parts

1.588 Ko.

99.25

Mortar, ditto, ditto, well beat together .. ..

1.903 Ro.

118.93

Mortar, of pounded tile 3 parts, of quicklime

2aparts......................

1.457 Ro.

91.06

Mortar, ditto, ditto, well beat together .. ..

l.663 Ro.

103.93

Mortar, common, of chalk, lime, and sand, dry .

1.550 R.

96.87

Mortar, the lining of an antique reservoir near

Rome................

1.549 Ro.

96.81

Mortar, from the interior of an old wall at Rome

1.414 Ro.

88.37

Mortar, lime, sand, and hair, used for plastering, dry............

1.384 R,

86.50

Oolite. See Stone, Roe.

Peat (hard)..................

1.329

83.06

Pebble (English) ..

2.609

163.06

Pewter .....................

7.248

453.00

Pitch.................

1.150 P.

71.87

Plaster (cast)...............

1.286 Be.

80.37

Platina, pure.................

21.531 Th.

1345.68

Plumbago, or black-lead ..

2.267

141.68

Porphyry (green) ...........

2.875

179.68

" (red) .. ..

2.793

174.56

Potstone ..............

from

3.000

187.50

[to

2.768 K.

173.00

Puzzolana ........

[from

2.570

160.62

to

2.850 K.

178.12

Quartz (crystallized) ..........

2.655

165.93

Roe-stone. See Stone.

Name of Substance.

Specific Gravity.

Weight of a cub. ft. in lbs.

Road grit See Sand.

Sand (pure quartz) ......

2.750

171.87

.. river ......

1.8.6 Be.

117.87

„ River Thames (best)

1.638T.

102.37

„ pit (clean but coarse)

1.610 T.

100.62

„ „ (fine grained and clean ....

1.523 T.

95.18

Sand scraped from Lon-don roads (road grit)

1.494 T.

83.37

Sand, pit (very tine grained)

1.480 T.

92.50

„ River Thames (in.

ferior)......................

1.454 T.

90.87

Sandstone. Sec Stone.

Serpentine, Anglesey green

2.683 R.

167.68

„ Mackish green

2.574 K.

160.87

„ dark reddish brown...........................

2.561 K.

160.06

Silver, pure cast .. ..

10.474 Br.

654.62

„ standard .. ..

10.312 Th.

644.50

Slate, Welsh.....................

2.888 K.

180.50

„ Anglesey .. ..

2.876 K.

179.75

„ Westmoreland pale blue .. ..

2.791 W.

174.43

Slate, ditto, dark blue ..

2.781 W.

173.81

„ ditto, pale greenish blue............

2.768. W

173.00

Slate, ditto, blackish blue, used for floors ..

2.758 W.

172.37

Slate, Welsh rag ..

2.752 K.

172.00

„ Westmoreland, fine grained, pale blue..

2.732 W.

170.75

Slate, Cornwall, greyish blue..........

2.512 K.

157.00

Snow.....................

from

.128 Hu.

8.00

to

.192 Hu.

14.00

Stone, Bath (roe-stone) ..

2.494 K.

155.87

,, ,, .............

1.975 R.

123.43

„ blue-Has (limestone)

2.467 R.

154.18

„ Bramley-fall sand.

ston.........................

2.506 Re.

15662

Stone „

2.261 R.

141.31

„ Bristol stone .. ..

2.510

156.87

„ Burford (dry piece)

2.049 P.

128.06

„ Caen (calcareous sandstone) .. ..

2.108;

131.75

Stone, Clitheroe limestone

2.686 W.

167.87

„ Collalo, white (sandstone) .. ..

2.423 Re.

151.43

Stone „ ,,

2.040 R.

127.50

„ Craigleith (sandstone)

2.452 Re.

153.25

,, ,, .....

2.360 R.

147.60

„ Derbyshire (red fri.) able sandstone) ..

2.346 Re.

146.62

Stone, Dundee...........

2.530 Re.

158.12

,, ,, ............

2.517 T.

157.31

No. XXI. - continued.

Name of Substance.

Specific Gravity.

Weight of a cub. ft. in lbs.

Stone (grindstone) .. ..

2.143

133.93

,, Heddiug.stone, lax kind ...........

2.029 P.

126.81

Stone, Hilton (sandstone)..

2.177 R.

136.06

„ Kentish rag .. ..

2.656 Hu

166.00

„ Ketton (roe-stone)..

2.494 K.

155.87

,, ,, .................

2.058 R.

128.62

, Kincardine (sandstone)

2.448 T.

153.00

„ Limerick (black compact limestone) .

2.598 Re.

162.37

Stone, Pennarth (limestone)

2.653 W.

165.81

„ Portland (roe-stone).

2.461 W.

153.81

,, ,, ,, .....

2.423 Re.

151.43

„ ,, ,, .............

2.113 R.

132.06

,, pumice .....................

.629 R.

39.31

,, Purbeck ..................

2.680 W.

167.50

,, ,, ......................

2.599 Re.

162.43

„ Roach Abbey (mag. neslum limestone) ..

1.893 R.

118.31

Stone, Tottenhoe (calca. reous sandstone) ..

1.800 T.

112.50

Stone, Woodstock flagstone

2.614 K.

163.37

Name of Substance.

Specific Gravity.

Weight of a cub. ft. in lbs.

Stoue, Yorkshire paving ..

2.507 Re.

156.63

,, ,, ,, ...........

2.356 R.

147.25

Stonework, mean weight according to Belidor about ..........................

.. ..

107.00

Shingle..............

1.520 Hu.

95.00

Steel................

from

7.780

486.25

to

7.840 Th.

490.00

Syenite (Mount Sorrel) ....

2.621

163.81

Tile (common plain) ...

1.858 R.

116.15

,, ,, ,, ...

1.815 Be.

113.43

Tin, hammered .. ..

7.299 Br.

456.18

,, pure cast............

7.291 Br.

455.68

Toadstone (Derbyshire) ..

2.921 W.

182.56

Tufa (Roman )...........

1.217 Ro.

76.06

Water, sea ..........

1.027 Th.

64.18

,, rain............

1.000

62.50

Whinstone (Scotch)..

2.760 W.

172.50

Wood ashes...............

.933 P.

58.32

,, petrified..........

2.341 P

146.31

Zinc ...........................

7.200 Hu.

450.00

Part of the letters of reference are explained in a note to the preceding Table, the rest are as follows: Be. Belidor; Br. Brisson; Ha. Hatchet; Hu. from Hurst's' Surveyor's Handbook'; K. from Kirwan's 'Mineralogy'; Re. Rennie, 'Philosophical Magazine,' vol. liii.; Ro. Rondelet; and Th. from Dr. Thomson's 'System of Chemistry,' 5th edition.

In bodies of a porous nature, the specific gravity, as given by the greater part of the Tables consulted by the Author, is much above the real weight of a given bulk of the material, as compared with water. The cause of this difference is the absorption which takes place when the body to be tried is immersed in water. Let A be the weight of a body in air, W its weight in water, a the weight of water it absorbs, and S the specific gravity; then A/A+a.-W = S. When the absorption is nothing, or a = o; then A/A-W = S, which is the same as the common rule.

By the equation A/A+a -W= S, the specific gravities in the Tuble marked R and T have been determined. But this method does not apply to sand and other loose materials; therefore, to find the specific gravity of sand, a vessel which when filled contained a known weight of water, was filled with the sand to be tried, and weighed. The vessel used by the Author contained 1300 grains of water; therefore, as 1300: weight of the sand:: 1: specific gravity of the sand.

By the method of mixing equal volumes of water and sand, a solid specimen of quartz would be of the same specific gravity as its sand would be: but it is well known that a stone crushed into sand occupies more space than the solid stone did; and therefore the method is erroneous.

The specific weight of a cohesive earth, such as clay or loam, is best obtained by cutting a cubical piece, and carefully measuring and weighing it. This method is given by Kirwan in his ' Essay on the Analysis of Soils,' and is accurate enough for most practical purposes.