Method of producing Heat, Light, §c. from Pit Coal. 337 
cock under each of them, almost close to the top of the 
purifier; when one pot is burnt out by turning the cock it 
keeps all the gas in the purifier while the cover is removed: 
no plug is necessary in this method. When people are 
very particular, (especially when houses or accompting- 
houses are to be lighted,) and wish all smell to be destroyed, 
if they are not satisfied with washing it, and stil] think there 
is a little smell left, (and very little indeed, if any, will be 
left.) after the washing, a small trough may be added, made 
in the same way as the purifier, with sheets of iron across 
to force the gas through the pipe R communicating with it. 
This trough may be filled with water, with a few lumps of 
lime put into it, and this water and lime changed often. 
On the gas being forced through this lime-water, if there 
was any remaining-smell in it, this would completely take 
it away; and, as has been before observed, by changing all 
the waters now and then, and keeping this small trough 
constantly supplied with clean water and lime, the yas after 
passing it will ascend the pipes to the lights pure. 
ee 
Sir,—Havinc been from home, I was prevented from 
answering your obliging letter until this day.—I am much 
pleased that the Society have approved of ‘my specimens 
produced from pit-coal. I feel also highly gratfied and 
honoured with their reward. I hope to lay betore you, in a 
short time, an account of the establishment of a work that 
will be of sach magnitude, as will supply this part of the 
country with the oil or spirit, in sufficient quantity to su- 
parects the use of turpentine, &c. in japanning; and I do 
ope that in time works of the same description will be 
established through all Staffordshire, whose products will 
supply the place of a great portion of the spirit used in the 
kingdom, while the pitch will be of sufficient quantity to. 
form a great part of that article now used in the dock-yards. 
All I want is support from the great coal companies and- 
masters, to erect sufficient apparatus at the different works 
to preserve the tar at all the coke furnaces, and proper means 
to separate the spirit from the tar. It would be a great 
saving to the nation ; as in every one hundred and twelve 
pounds of coat coked, there is lost by the present mode about 
four pounds of tar, and the cokes are not half so good as if 
they were coked in close vessels, to the exclusion of the 
atmospheric air. I need not describe the method by draw- 
ings of the manner of extracting the tar from pit-coal in 
Vol. 37. No. 157, Magisit.. = Y¥ close 
