Prof. Hosking on Ventilation. 249 
which should be more minute than if designed for English read- 
ers, can be translated and printed very easily in this country. 
But there would be no difficulty in printing the directions by 
means of wooden blocks in the manufactory at home.. In copy- 
ing the characters for the astronomical characters or descriptions 
of any kind which may be needed by individuals trying the ex- 
periment of clock making for China, I shall furnish most cheer- 
nese, they have never constructed one for themselves? It is 
certainly marvellous that they should manufacture clocks, includ, 
ing dial plates, and always employ Roman figures, and follow 
the reckoning of foreigners, which so few of them are able to 
comprehend, and which by all are considered mysterious and 
outlandish. . It is only to be accounted for on the ground of their 
limited inventive abilities and high powers of imitation, That 
a time-piece of this description would be in demand in China, I 
am perfectly satisfied, from inquiries made of natives in various 
quarters. Chinese merchants say that they should be retailed at 
about $5 or $6 each. If L recollect rightly they can be made in 
Connecticut at $2.50, which would afford sufficient profit both 
for the mechanic and the merchant. 
Ningpo, July 4th, 1851. ior: 
Arr. XXV.—On Ventilation by the Parlor Fire; by Wru11am 
oskine, Esq., Professor of Architecture and of Engineering 
_ Constructions at King’s College, London.* 
oy 
wind—we are apt to put ourselves upon a short allowance of air 
and to eke out the short allowance by using the same air over 
and over again. | ? 
There is a broad line of distinction, indeed, to be drawn be- 
tween in-door and out-door ventilation ; for although the princi 
Ples upon which nature s are the same, the operation 1s 
ct ee ae, ee em 
Szconp Series, Vol. XIII, No. 38—March, 1852. © 82 
