Notices. 
477 
rating steam of high temperature and great expansive force, to 
waste itself in the open air, and in its exist to be counteracted by 
the resistance of the atmosphere, are thrown aside. The faults 
both of the European and the American engines, are in a great de- 
gree obviated ; and we may expect from American ingenuity, a, 
more perfect engine than has yet been devised. 
The engine in contemplation, will act by steam at high tempe- 
rature, as Watt suggested, and Trevethick practised on a large 
scale ; it will act by expansive force as has long been the practice 
in many English engines ; and by two cylinders : so as to combine 
the modern improvements, and obviate modern defects. How far 
Mr. Dowers has been indebted^ if at all, to his predecessors, the rea- 
ders must judge by the references I have made to former pages 
of the present volume. 
I shall indeed rejoice to see some American by and by, still inr« 
prov§ upon his ideas. T. C. 
NOTICES. 
Stone Coal. Judge Gibson, of Luzerne, has written me the 
following letter. 
Wilkesbarre^ February 23, 1814. 
Dear Sir, 
I send you a likeness of one of your friends. There iss 
nothing remarkable in it, except that it is done with the stone coal 
of this place, instead of Indian ink. It is prepared for use by rub- 
bing a bit of it on a fine hard stone in gum water, just thick enough 
to hold the particles in suspension ; it is then laid on in the usual 
way with a camel hair pencil. By comparison with a drawing in 
force will diminish the size of boilers ; when unwieldy beams and ponde- 
rous fly wheels will be disused ; when single engines will give place to dou- 
ble, when expansive power will be use*d to the utmost; and when no steam, 
will be generated to be throwii away. As yet, I dare not anticipate the time, 
when water will be laid aside, and alcohol, ether, alkaline gas or hydrogen be 
substituted in its place. Alcohol and ether are condensible at Ipw tempera- 
tures— Ammoniacal gas by the vapour of muriatic acid— and hydrogen, 
by firing it witli oxygen, and converting it into water. These are speciir-i' 
tions ; and so was at one time, the steam engine itself. T, C. 
YoL IL 3 F 
