1825.] 
or lost masts. Mr. Rice is going out with 
a set of these masts to South America, to 
superintend their fitting in the Spartiate 
man of war of seyenty-eight guns, which 
lies there, disabled, from rotten masts ; and 
afterwards to sail in her, and observe care- 
fully, and report on, their sufficiency in 
blowing weather, &c. 
The History of the Earth, “‘as determined 
by the documents of geognosy,”’ according 
to the Rey. Dr. Fleming, (Jameson’s Jour- 
nal, No. 23), teaches that “the surface of 
the earth is, at present, in an unnatural 
condition. Mountains rise above the level 
_ of the sea, and hollows exist beneath its 
level.” But causes “ are operating in 
bringing the earth into a natural state, by 
wearing down the projecting parts, filling up 
the hollows, placing the surface every where 
at right angles tothe direction of gravity, and 
perfecting the form of the earth as a sphe- 
roid of equilibrium.” Fortunately, for the 
future generations of mankind, the doctor’s 
perfecting process is but a chimera of his 
own brain; and there is no reason to fear 
such a state of things, when the present 
bed of the sea being entirely filled up, and 
eyery mountain and hill levelled therewith, 
its waters shall again, uniformly, cover the 
whole globe, as they did at the epoch indi- 
cated in the first verse of Genesis ; for the 
rivers carry no solid matters whatever into 
the depths of the sea; and only the most 
inconsiderable quantities of mud are borne 
by them into the tidal estuaries. The waves 
of the sea break down the projecting points 
of some of the hills on the coasts, forming 
there decaying cliffs, and bear their argil- 
laceous ruins to the nearest bays and estua- 
ries; and this is almost the only change of 
form now going on, or which has gone on, 
upon the earth’s surface, since man began to 
exist upon it: otherwise, the doctor might 
have. been able, in “ the modern strata,’’ 
of which he writes (in the Journal referred 
to), to have pointed out instances of the 
remains of man, or of some of his handy 
works, in or under the diluvium, which 
neither he nor any one can; and much 
less do any such remains exist, in the regu- 
lar strata, beneath the diluvium. 
Electro-magnetic Action, transmitted through 
various Lengths of Wire, has been the sub- 
ject of an elaborate course of experiments, 
by Professor Barlow, which are detailed in 
Jameson’s Edin. Phil.. Jour., No. 23; 
whence he infers that the natural tangents 
of the angles of deflection of the compass- 
needle are in the inverse ratio of the square 
roots of the lengths of the conducting wire. 
In another course of experiments, for de- 
termining the effect of the size of the con- 
ducting wire, the professor was not alike 
successful: wires below a certain size 
seemed to impede the electro-magnetic ac- 
tion ; but above this, the increase in dia- 
meter of the wire seemed to produce no 
effect. 
Spirit of Philosophical Discovery. 
59 
Maximum Density of Water.—Some very 
ingeniously contrived experiments, by Mr. 
James Crichton, on the density or specific 
gravity of water, are detailed by him in the 
“Annals of Philosophy.’ Small hollow 
balls, or drops of glass, were so adjusted, as 
to be exactly poised and remain in equilibrio, 
in any part of a tall glass of distilled water, 
at a point about 32° of Farenheit: the water 
was then gradually heated, to some other 
point about 52°; where the same ball, after 
haying risen to the surface and again begun 
to sink, would again be exactly poised. A 
great number of these experiments being 
made, with different balls, and with diffe- 
rent degrees of heat at the times of poizing 
the balls, the mean degree, in each of: the 
experiments, was found to concur in shew- 
ing, with surprizing uniformity, that dis- 
tilled water, at 42° 3/ of Farenheit, is in its 
most concentrated or densest state. Some 
years ago, 40°, but latterly 39°, has been 
mentioned by authors, as the temperature 
of water, when at its greatest density ; 
whence it will appear, how important the 
correction is, which Mr. Crichton has here 
made. 
The Elasticities of Steam of different Tem- 
peratures, haye lately been stated, by a 
committee of the Royal Academy of Paris, 
to whom had been referred various inquiries 
as to accidents arising from the bursting of 
steam-engine boilers, in a Table, which has 
been reduced to English measure and 
weight, in Mr. Brande’s Journal of Science, 
No. 36, as follows, viz. 
Measures of Elasticity in 
Pressures on Columns of Temperatures, 
a Square  Mercury,in in Degrees 
Atmos- Inch Eng.in English of 
hs acl. ane Eo 
6 “92 212°0 
13 21°92 44.88 2340 
2 29°23 59°84 251°6 
24 36°44 74°80 264-2 
3 43°84 89°76 275°0 
34 51°15 94°73 285°3 
4 58°46 119-69 293°4 
42 65°76 13465 3020 
5 73°07 149°61 309°2 
53 80°37 164°57 3164 
6 87°69 17953 322°7 
64 94°99 194°49 328°5 
vi 102°30 209°45 334-4 
74 109°60 224-41 339°3 
8 116°92 239 °37 343°4 
The Composition of Ou-gas appears under 
a somewhat new aspect, since the conclu- 
sion of Mr. John Dalton’s course of experi- 
ments on oil, and the gases obtainable from 
it by heat, which has lately been printed in 
the Memoirs of the Manchester Society. 
Mr. Dalton having detected a new gas, as 
a component of oil-gas, whose elements are 
the same as those of olefiant gas, but which 
has suffered a greater condensation, in the 
ratio of 4: to 3, and which new gas he de- 
nominates super-olefiant gas: and states the 
constitution 
