Chemical Examination of Bituminous Coal, 373 
Rumford caused balls to be made of clay and fine coal moistened 
and kneaded together, the object being not only to economize 
the waste coal, but also to accumulate and radiate the heat. 
As in the Mid Lothian coal there is very little iron, it is not 
likely that the ashes will readily form slag or clinker to obstruct 
the bars of a grate, or to accumulate like a fungus, upon the walls 
of a furnace. 
Should there be occasion to convert the Mid Lothian coal into 
coke, it would afford that very important fuel of an excellent 
quality. If the. process were conducted at a low heat, it is proba- 
ble that a very brightly burning gas would be obtained, fitted 
for illumination, especially if it were mixed with a requisite pro- 
portion of the gas from rosin, as is done in the gas works in Bos- 
ton, where Pictou coal of Nova Scotia is employed for this pur- 
pose. ‘I'he Mid Lothian coal contains so little sulphur, that for 
every practical purpose it may be regarded as free from that com- 
bustible which is so injurious to the working of bar iron and steel 
by the forge and hammer, especially in the very important opera- 
tion of welding. From repeated trials made with the Mid Lo- 
thian coal by our smiths in this city, it appears perfectly well 
adapted to their uses, especially where a hollow fire is desired, 
and when a powerful heat is necessary for large work witha 
strong blast. One of our best smiths, having made a comparative 
trial of the two, remarks, that it does not ignite as soon as the 
Neweastle coal, but gives a surer good welding heat, and lasts 
hearly one quarter longer. 
This coal is an excellent fuel for a parlor grate. No bitumen 
exudes during its combustion; on breaking a heated mass by 
the poker, there is no liquid tar covering the separated frag- 
ments, but a bright flame instantly kindles on the newly exposed 
surfaces, which radiates heat powerfully and illuminates the room 
with a cheerful radiance. : 
There being no liquid bitumen, the combustion of this coal is 
attended with less smoke than is usual with bituminous coals; 
with a well drawing vent, there is scarcely a perceptible odor and 
no deposit of coal dust in the room and upon the furniture. 
rom a considerable experience in using it by us in a family 
parlor, it proves to be a very desirable fuel. We presume that it 
would prove an excellent fuel for locomotives and for steam en- 
gines, as it is abundant in flame so important to the production of 
