a2 Anibracie Coas of Pennsyloanw. 
different from any other anthracites. They are also very 
pure, in quantity inexhaustible, and accessible in the easi- 
est and least expensive manner.* 
Tam not able at present to say any thing of much impor- 
tance, as to the Rhode Island anthracite. A quantity whicli 
had been promised to me for comparative experiment not 
having arrived, | have not been able to compare it with the 
Pennsylvanian anthracite, except as regards the gas. I hope 
to make these trials before the season is through, and cannot 
doubt that the Rhode Island coal will prove an important 
addition to our national resources, especially with the aid of 
the practical knowledge which has now been so extensively 
obtained, with respect to the use of the anthracites. 
In the domestic use of the anthracite, for warming, where 
enly one reom of moderate size is to be heated, there are 
peculiar advantages in using a parlour grate, but there is no 
doubt that the most comfortable method of diffusing heat 
through two or more apartments is by placing a close stove 
er furnace in an entry-hall or recess, or in some small apart- 
ment, which may be given up, to be used as a stove room, 
and with which other rooms are made to communicate by 
doors. It is not necessary, as some suppose, that a tube 
should pass into a room which is to be warmed ; this will in- 
deed increase the effect by means of radiation, but the circu- 
lation of the airis quite sufficient without radiation,} and no 
one wishes to see an iron tube pass through a handsome 
apartment. In future, those who construct houses, in situa- 
tions where the anthracite can be economically obtained, will 
do well to have reference to warming their apartments froma 
central situation. It is, however, necessary that the communi- 
cation from below.with the chambers should:be so arranged, 
that it can be opened and shut at pleasure. If it cannot be clo- 
sed, the lower rooms are occasionally chilled by the descent of 
the cold air from the apartments above, and the, latter are oc- 
casionally too much heated from below; but a door, like a 
valve in mechanics, enables us to preserve the equilibrium, 
and by shutting duors leading to other rooms, any one apart- 
ment connected with the source of heat, may be immediately 
heated forjuse, and others in succession, as they are needed. 
In houses having a hall through the middle, it is necessary 
*See Mr. Maclure’s remarks on this topic, page 205 of this volume. 
} Direct radiation, except in a very large room, would prove incon: 
vemientiy pewerful opless the stave were very smail. 
