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 7% 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, of Virginia bituminous coals. 
Density Composition in 100 parts. 
US : i>) =) no} 
52 3 ‘By 2 < De a 2 
ve) = fo = S 
shies] S82 | fees 5 32 
[eo aol eee os seal] s. ee 
: i Pal] SSSRShSI| csital |! Gia |) Sy pe a Se . 28 
Designation of coals. 2) 58 |es| s g\/-s ae ge | a 5 é B lye 
E "sp n ~~ te) To] 2 = 
B| S2teo| 29 | So|ue bse | se 8 3 [32 
to] x oo Be fg sl (S10 ln Pa : g n 
oi 2 a bees |isay Pye ee (oh | aS] s| a we 
epi e) HERO) Se ee aes Eps @ 5 cS) > |o28 
Spee ee) Se op ee ieee | S| |) 5 eats 
a| sp joS|me}o |2 esis a hs |) St avian 
Pee |S) | Sele wlan) SS m| &® | 0 | a Is 
Bata Wika alfa It nl 
Barr’s Deep Run, - - - - (1382 86-410 48 |53-174 06153 6153 42-126 1785'19-782| — |67-958/78-433 10-475 ATS 3-425 
Crouch & Snead’s,- - - 1-451) 90:710} 36 |53°593|0-5908'41:797|1:785|23-95910-427|59-976|74 256 | 14-280) 2: re 
Midlothian (900 feet shaft) a av- 
erage coal, - 1:437|87:497] 34 |50-518)0°5773 44-340!1:172|27:278] - |61 083/71 550/10°467/2:289 
Creek Company’ Ss coal, - 1:319)82°480} 41 |46-496|0-5636 48:170/1°450/29-678)2°890/60°300)/68-872) 8:572)2-032 
Clover Hill, - - 1:285|80-355| 42 |45-485|0-5660!49-250]1-339/31-698]0:514156- 831)66- 963) 10°132)1°793 
Chester field Mining Company, 1-239 80°565) 43 |45°549)0-5653'49-180}1 -896|30°676)1-957|58:79467-428] 8:634/1-917 
Midlothian, avera age, - |1:294)80°895| 42 |54:044)0-6680.41-450/2:'455/29-796/0:058/53-012)67 -749)14-737|1-780 
Tippecanoe, - - - |1-346|84-140) 55 |45-100|0:5360!49-670]1 -841/34-165|0:377|54:620)/63:994| 9:374|1:599 
Midlothian, ‘new shaft,” |) 325/82°815] 31 |47:899|0°5811/46°760/0°670|33:490|2-286/56-400)/65°840} 9-440) 1-684 
Midlothian, screened, - - - /|1°283/80°210| 46 |45°722|0:5700.48-990/1°785|34-497/0-202/54:063/63°718) 9-655) 1567 
Midlothian, (navy yard,) - !1:390|86°S55| 15 |54:468|0-6271/41-125}1 014|28°736/2-380]56°112|70:250/14:138]1-953 
