338 
the quantity of fuel, and three times the 
space for stowing it—besides the additional 
space occupied bya larger engine :—this is 
rather an unexpected result, and well may 
he say, that it exhibits the subject in a 
‘striking point of view. This gentleman 
proposes to remedy the imperfect draught 
of the chimney, by the introduction of an 
‘artificial blast, so directed as to force the 
fldine to expend its heat on the boiler. Mr, 
Ti urges it On the attention of those who 
wish to extend or improve this kind of na- 
yigation, to adopt more effectual methods 
to confine the heat more exclusively to the 
region of the boiler, and particularly, with 
regard to the engineer and firemen.—Jbid. 
Aerolites.—Mr. Rose, of Berlin, has se- 
parated well-marked crystals of angite, of 
“fig. 109 of Haiiy’s Mineralogy, from a large 
specimen of the Javenas aerolite, appearing 
‘to contain crystals of felspar with soda, 7. e. 
‘of albite. He also finds the olivine of the 
Pallas meteoric iron perfectly crystallized ; 
‘and the trachytes of the Andés mixed with 
angite and albite.—Jam. Ed. Ph. Jour. 
Hydrometrograph, for measuring and re- 
cording the quantity of water, or other 
fluid, discharged within a given time. <A 
‘machine of this kind has been invented by 
“Chev. J. de Baadar, of Munich; under 
whose management are placed the Royal 
Bavarian salt-works at Reichenhall and 
Traunstein.. The idea arose from the ac- 
knowledged want of an exact measure for 
great quantities of brine, which could only 
‘be-imperfectly computed by the ordinary 
method. It was, therefore, very desirable 
-to invent a perfectly correct and infalkible 
-measurer of the quantity of fluid delivered in 
any given time; which, it seems, the expe- 
rience of many years proves to have been 
- » done, in this instance, in a most successful 
manner. The use of the instrument (which 
ean be constructed on any scale) is recom- 
_mended in this country, either for measur- 
ing the largest or the smallest quantities of 
. water and other fluids,—for registering the 
supplies of water-works, or stream of 
water, actuating a water-wheel, or in the 
irrigation of land,—for measuring and re- 
cording the quantities of wort or beer in 
breweries, or of brandy, &c. in distilleries, 
even down to pints and cubic inches: and 
-also in meteorology, as a convenient and 
» elegant measure of rain, —-Ibid. 
Steam Coach.—Messrs. Burstall and Hill 
have inyented and completed a Locomotive 
. Carriage, though so recently that it has not 
-been sufficiently experimented, but the lead- 
ing principles of which may be compre- 
‘yhended under the following heads :—lIst, 
the arrangement of machinery, and certain 
“pieces of mechanism, adapted to effect the 
_ Necessary evolutions of a locomotive car- 
riage; 2dly, the novel construction of a 
_boiler, or generator, for the production of 
Steam, and the peculiar kind of pipe, or 
urved passages for conducting the steam to 
' Spirit of Philosophical Discovery. . 
[ Nov. 1, 
the engine; and, 3dly, the mode of supply- 
ing the boiler with water, by means of pneu- 
matic pressure. It is proposed, in the pe- 
culiar construction of the boiler, to. make ita 
store of caloric, heated from 250 to600 or 800 
degrees, Fahr.: keeping the waterin a se- 
parate vessel, and only applying it to the 
boiler when steam is wanted, the great ob- 
ject is attained, of generating just'se much 
steam as may be required; so that when 
going down hill, where the gravitating force 
alone is sufficient to produce the requisite 
quantum of motion, all the steam and heat 
may be saved, and accumulated to be given 
out at the first hill, or bad piece of road. 
These engines are called high-pressure, ca~ 
pable of working to ten-horse power (it is 
usually calculated that the action of one 
horse is equivalent to raising 32,000 Ibs. of 
water a foot a minute), and the steam is to 
be let off into an intermediate reservoir, re- 
gulated by one or more cocks. 
Effects of Mildew on Canvas.—It is welt 
known, by those concerned in the manufac- 
ture and use of canvas, how deleterious is ~ 
the effect of mildew upon it. Exposure to 
the influence of damp, in a store-house, 
cellar, or the hold of a vessel, and more 
especially to continued moisture, as in that 
part of a tent which is in immediate contact 
with the ground, or when sails have been 
rolled up or stowed away wet, in the hurry 
of a storm, &c., produces mouldiness, dark- 
coloured spots and rottenness: this Dr. 
Greville has considered to be caused (in 
part, at least) by a minute cryptogamie plant : 
of which he traced the subglobose and 
transparent sporules, though the filaments 
were indistinct, adding, “ from the nature of 
the whole tribe of these plants, I do not 
think the present one would have been pro- 
duced, except the canvas had been pre- 
viously in a damp state.’’ The prevention 
‘ of mildew and rot in canvas has for more 
than half a century occupied a considerable 
portion of attention: but considerable dis- 
advantages have attended the processes hi- 
therto devised. Mr. Sanderson, of Leith, © 
professes to be in possession of a method 
(antiseptic), of which decisive and highly 
satisfactory trials have been made; and 
which is retommended “ as completely effi- 
cient under all ordinary circumstances.”’— 
Preserving Anatomical Preparations.— 
Dr. Macartney of Dublin substitutes a thin 
plate of Indian rubber, as a covering for the 
Jars, in place of the former troublesome and 
offensive use of putrid bladder, sheet-lead, 
&c. It is essential that the Indian rubber 
should be painted or varnished; after which 
not the slightest evaporation takes. place. 
Perhaps leather, coated with Indian rubber, 
and painted, would answer? ... 
Glass Chimneys ‘are now iw*such com- 
mon use, not only for. oil-lamps, but for oil 
and coal-gas burners,’ that \(i lent of 
the danger to those néar ‘them} n they 
burst) the destruction “of thear bécomes a 
: matter 
