The Sun.
London, England, 1826-05-06 00:00:00

SCIENTIFIC INTELLIGENCE.

ROYAL. SOCIETY, MY 4.
At the Meeting this evening, a Paper was read by Lieutenant
DrUmmond, on the method of facilitating the observat:on a
44iistant stations in geodesical operations.
In all trigonometrical surveys, the greateet • 'source of difficulty
and delay (especially in bad climates) has been the itnpracticabili-
ty of distinguishing the stations, excert in clear weather. To
remedy this evil, several expedients have been proposed. Those
here described are of a twofold kind—the tint eonsists.of a,inireor
so mounted as to be capable of turning with the sun's motion, so as
to throw its rays exactly in the hoe to the observer at the distant
station. This has been found efficacious even in the most hazy
state of the atmosphere, at distances of nearly 60
The second method consists of the new plan of producing !nil-
liant light, which we mentioned a few days ago.. 'Various forms
of combustion, &c. had been tried without effect; the plan at last
which was found to succeed consisted in beating to incandeNcence
small balls of lime or magnesia,&c. (lime being found to an.swer beet),
by the flame of a spirit lamp urged with oxygen. The light thuspro-
duced was found, by comparison, more intense than that of the
brightest lamps, &c. in a very high ratio. In one instance, (when
placed in the focus of a reflector) the eye could hardly bear it at
40 feet distance. Some instances of its perfectly successful appli-
cation in surveying operations were given.
Some experimexits were also subjoined on the chemical proper-
ties of this light, which are highly interesting. It was found to,
resemble the solar light in having an action upon a mixture of
chlorine and hydrogen; and when analystsl, its violet ray blacken,
ed muriate of silver—properties which have hitherto been found
in no other light than in that of the sun and of galvanism.
Some additional expel intents are given in a postscript by Mr.
Herschel, in which the optical properties of this light, as exhi.;
kited in its prismatic spectrum, are detailed.

IMroaTANT DISCOVERY.—One of the greatest discoveries ,yet
made in navigation has transpired, although the patent has been
abandoned in consequence of the technicalities of the patent laws,
and the probabilities of litigation.—Three-fourths of the fuel now
used in steam-navigation will he saved, the vapour of quicksilver
is substituted fur steam with similar maehinery, and a few pre-
cautions to prevent any aste of the metal by a piPe on the safety-
valve, &c. The bottom' of the boiler, 'which is ve§, aniall and
strong, as compared with that now m use for pi-of*k, steann, it
conical, and the termination c,f Ito cone is ili.COutaet w,th tilt
burning coals, which surmount it; their 414 is communicated
almost instantaneoasly .to the quicksilver in the boiler, thi
it into vapour, At the temperature of tis 6 deg. of Fahreuiwit. It 4
elasticity and power can be indefinitely increased by heat, awl th'e
greater the elasticity produced, the greater the vacuum in the cy-
'limier on opening. the valve communicating with the. well. ; The
saving of stowage will be very considerable, and a ton
,of quick-
silver will be sufficient, for propelling a WWI to India mid fiack
again, With 14.0 horse power.