Miscellaneous Intelligence. 293 
and Clement asa mean. As 560° C. =990 
990°-+-2 12° — 60°=1142°, 
for the qnantity of heat necessary to convert water at 60° into steam 
at 212°. 
4. Note to p. 226, on the Theoretic Determination of the Expenditur 
of Heat; by Prof. Barnarp.—A partial compensation for this ex- 
penditure, arising from expansion after cut-off, overlooked in the text, 
seems to be of sufficient importance to deserve attention in this post- 
script note. When the supply cylinder is less than the working cylin- 
der, the density of the heated air is, at the end of the stroke, necessarily, 
in the same ratio, less than unity. In this case, it is 3. Now this air 
cannot be discharged at a less pressure than that of the atmosphere ; 
and, in the general formula, 
6 
p'=0(4+ sa) 9, 
canique) puts it at 550° C., adopting the determination of Désormes 
s 560° ° F., we have 
6 6 
519 must be equal to 3; or 519 to 3. 
That is, 4 must be 259°-5 above the initial temperature, (60° F.) or 
289°'5 above 32° F. 
If we put p/=p, and 9=§, 1+ 
apparent consumption, as given in the text; leaving the actual theoretic 
consumption, an amount representable in mechanical equivalents, by 
186-3 MK,=136-98 MK,—82°56 MKyw. 
_ Putting M—46°82 Ibs., we find the consumption of heat to be suffi- 
cient to raise one pound of water 1524°-5 F., or to convert 1-335 Ibs. 
into steam at 212°, which is adequate to raise 76-880 Ibs. one foot, and 
es the power of steam to that of air, as ‘81. 
Allowing the steam an equal expansion, the ratio becomes 1: 4556. 
- The relative theorelic economy of steam and heated air employed 
as motive powers is apparently, therefore, not materially affected by 
varying the ratio of the supply to the working cylinder. . 
5. On a Native Boro-titanate; by Prof. J. Lawrence Smitx."— 
under the name of Warwickite, and considered as a hydrated ea 
titanate of magnesia, iron and alumina. It was afterwards « ae 
by Mr. T. S. Hunt under the name of Enceladite, and in his last analysis 
_* This important paper was received at too late an hour to be inserted earlier in 
