Review of Prof. Johnson’s Report on American Coals. 321 
“This great increase in the rate of expansion of water above the 
boiling point, being nearly 74 times as great in the range of the 
last 7° as in the first stage of 40°, may probably possess some in- 
terest beyond that which attaches to it as a means of correcting 
the results of certain observations taken during this research. 
The subject has not, to my knowledge, attracted much attention 
among experimenters. It will be remarked, that this rapid aug- 
mentation of the rate of dilatation of water, in iron is not prevented 
by the conversion, at the same time, of a considerable quantity of 
water into steam of a high density.” 
A synoptical table of the character, composition and efficiency 
of each class of coals follows the tables relating to each member 
of that class. The following, relating to the bituminous coals of 
Virginia, near Richmond, we introduce also as the best means of 
exhibiting its object and importance. 
Synoptical view of the characters, composition, and efficiency, x, fe bree bituminous coals. 
> usity. | in 100 p: | 
0 ’ . r2) mo sS 
SPS te +2 ore oma : 2 
asics |2./8 |3 sis S. 
Se leebee bee |e (8B) » 35 
see eeie | ke les] 2 SS 
yes t2'6é a ° oS lfsals. o 
S| oS (E2158 | on] So [ES] os . |24 
Designation of coals. S) So lo=} se) $s) Ba ls2] o8 : & logo 
=| sa les| 2k | em] &o jew| se § = |33 
| Sales| 23 | e| ce ee | 28 3 = \a¢ 
Sl ee |Pslch| oFl SSisF| ges = a AWS 
= ao io pele x 25 BY ia =| ) & os 
| ge |Us) rs Moles s = z 5 S ig 
aHEe 2 les|s |3|e|2|& 8 
wa) Saié6 S s = a m| & <) 
aie |e |e 5 
s Dee ep Run 1-382 86°410, 48 |53-174/0-6153 42-126}1 785|19°7: 67 -958;78-433 10°475 3 
Cietk & Snea “73 1-451| 90-710} 36 }53-593|0-5908' 41-797|1-785|23-95910-427 |59-976|74-256 14°280/2- 
Midlothian (900 feet shaft) a av- | | | 
€rage coal, - - - - - 1-437) 87'497| 34 |50-518 0-573 44-340 1°172)27°2 7 10°467 2 
Creek Company’ 's coal, 1-319, 82°480) 41 |46-496|0°5636 48-170)1-450/29 68 | 3: 
Clover Hil], - 1-285} 80-355] 42 |45°485/0°5660 49-250/1-339)31 
Chesterfield Mining Company, 1-289, 80°565) 43 |45-549/0-5653 49-180}1 ‘896/30°6 
Midlothi ge, 1-294} 80°895| 42 |54:044/0-6680 41 -450/2-455/29-7 
Tippecanoe, - -.- = - + 1°346|84+140) 55 {45°100/0 5360 49-670}1-84 1/3472 
Midlothian, ‘new shaft,” - |1-325/82-815| 31 |47-899|0-5811'46-760/0-670/33 
Midlothian’ screened, - |1-283|80°210) 46 5°722/0°5700 48-990)1" ey 34 
Midlothian. (navy ya ard, ) 1:390186°855| 15 [54° 014/28" 
