L A 
by the piece g. h i is the wire by which the lamp or 
burner is fufpended. 
Barton's Lamp, 1810. Mr. John Barton, of Argyle-ftreet, 
Weftininller, has taken out a patent for a lamp conllrucled 
upon the natural unerringprinciple of the difference of gra¬ 
vity between twofluids; which producesa conftant fupply 
of oil, or other combuftible fluid, to feed the wick thereof, 
fouriling in a perpendicular direction from a refervoir be¬ 
neath the flame, having the quality of burning or con- 
fuming tile whole oil, or other combuftible fluid. The 
method of railing the oil, Sec. confifts in applying to the 
bottom of the column of oil, or other combuftible fluid, 
contained in the lamp, the hydfcftatic preflure of a fluid 
of greater fpecific gravity contained in an exterior reler- 
voir, in which the lamp itfelf, with its contents and appen¬ 
dages, is made to float; and which fluid of greater i'peci- 
fic gravity communicates with the interior of the lamp it¬ 
felf, and is at liberty to flow into it, fubjeit to the coun¬ 
teracting hydroftatic preflure of the column of oil, or other 
combuftible fluid, contained in the lamp, by means of an 
aperture in the bottom of it; and the patentee adds, “I 
am induced to believe, that, by making the point at which 
the wick is placed, moveable; by the continual fubfidence 
of the lamp on the exterior refervoir, during the combuf- 
tion of the oil, See. and by the other improvements in 
the conftruction ; I render it unneccffary, in the majority 
of inftances, to employ for the heavier fluid any one 
of greater fpecific gravity than common water, and in 
other refpefts accomplifli the end propofed with greater 
advantage or convenience than the fame has hitherto been 
done with.” The lower part of a hall or ftaircafe lamp, 
is a cylindrical veflel of thin brafs or copper, the bottom 
of which is fitted on its lower extremity, either by a ferew, 
joint, or otherwife. From the top of this veflel there if- 
fues a tube, communicating with it, to the fuperior ex¬ 
tremity of which the burner, or burners, are adapted. 
There is a air-veffel or float, nearly, but not quite, fufH- 
ciently buoyant to fupport the whole of the lamp (that 
is, the veflel with the tube, and the burners attached to 
its fuperior extremity) in water, or fuch other fluid as it 
maybe thought proper to life, for the purpofe of fupport- 
ing the neceflary column of oil by its hydroftatic preflure, 
when the cylindric veflel is filled with either oil, Sec. 
There is alfo an additional float fitted on the tube towards 
its fuperior extremity, which is fo adjufted as to be ca¬ 
pable, together with an inferior float, of fupporting the 
whole of the lamp. The floats may be made of any buoy¬ 
ant fubftance, capable of being adapted to a like purpofe; 
fuch, for example, as the lighter kinds of wood varnifhed, 
or cork; or they may confill of tin-plate, thin brafs, or 
any other thin metallic plates, foldered- up, fo as to form 
a hollow air-tight veflel. The exterior part of the lamp 
ferves to contain the fluid, by the hydroftatic preflure of 
which the neceflary column of oil for the fupply of the 
burners at the fuperior extremity of the tube is to be fup- 
ported; and in v^hich the lamp itfelf, with its tube, the 
burners, and the floats, are intended to float when the 
veflel and tube are filled, either with the oil originally in¬ 
troduced into it, or with fuch refidue of it as may from 
time to time remain unconfumed ; together with fuch por¬ 
tion of the water, or other fluid heavier than oil, by the 
hydroftatic preflure of which the column of oil is intend¬ 
ed to be fupported. It mult be obferved that, whatever be 
the fpecific gravity of the heavier fluid, the relative heights 
of the whole of the veflel, with the tube, muft be in a 
fomewhat greater proportion than the inyerfe proportion 
of the fpecific gravities of thofe two fluids, to enable the 
cotton to produce, by its capillary action, a fufflciently- 
copious fupply of the oil, Sec. The patentee next gives 
a method for conveniently filling the veflel ; and he adds, 
that the burner confifts of a tube tapering upwards, to 
the upper part of which, and not more than about one- 
half its diameter below its fuperior extremity, there is at¬ 
tached a fmall plate or ledge, concave upwards, and pro¬ 
jecting on every fide from the exterior of the tube itfelf 
Vai,. XII. No. 815. 
M P, Ill 
to a diftance equal to about one-half of the diameter of 
fuch tube. The intention and effeCt of this projecting 
plate or ledge, are, to catch the fmall quantity of oil which 
generally exudes from the wick of a lamp that is fuftici- 
ently fupplied, and by that means not only prevent the 
unpleafant effeCt which refults from the flowing of the oil 
down the fidcs of the burner, but apply the oil, which 
would otherwife be wafted by this means, to the purpofe 
of more copioufly fupplying the combuftion of the wick. 
In order, however, both that no part of the oil which ex¬ 
udes from the wick during its combuftion may be wafted, 
and that the difagreeable efleCls which would refult from 
its flowing down the fides may be (till more effectually 
prevented, Mr. B. attaches-to the tube which conftitutes 
the burner, at a convenient diftance below the plate or 
ledge, a fecond plate or ledge, of the fame figure, but of 
larger dimenfions than the one already deferibed. The 
tube which conftitutes the burner, is perforated between 
the two plates with two or more horizontal circular rows 
of fmall apertures, furrounding fuch tube; by this con¬ 
trivance, any fuch oil as efcapes over the edge of the up¬ 
per of the faid plates, may be caught by the lower one, 
and by that means again brought into contaCt with the 
wick through the apertures ; and alfo, the external air 
which is admitted through the apertures, and a certain 
quantity of which will, of cbnrfe, rife through the in- 
terftices of the cotton to the lighted portion of the wick, 
will aflift in promoting combuftion. 
Travelling Lamps. Dawfon's carriage-lamps can be made 
to any (hape or pattern. A defcription of a four-fided 
one will convey to the reader a proper idea of the inven¬ 
tion. Two fides are of courfe dark, with refteCtors, the 
other two of glafs. According to the old conftruCtion, 
there were Aiders before the glafs, which were the occa- 
fion of feveral inconveniencies. Mr. Dawfon, to prevent 
the neceflity of thefe, makes his lamp to confift of two 
parts, namely, the lamp itfelf, and a cafe ; the latter is 
fixed to the carriage, and the former is eafily taken in and 
out, and, being made exaCtly fquare, in the day-time the 
dark fides are outwards, which prevents any damage hap¬ 
pening to the glafs : and at night the glafs is inftantly 
turned outwards, and candles or oil may be ufed at dif- 
cretion ; another advantage is, that, in cafe of any acci¬ 
dent to the carriage by night, or of any thing loft, Sec. 
the lamps may be taken very readily from the cafes, when 
they make admirable hand-lanterns. 
We (hall give a few figures to explain the conftruCtion. 
Fig. 3 reprefents a circular lamp or lantern, made to fit 
into, and turn half round in, figs. 4 and 5.; and, when 
united or joined by folder or otherwife, forming a cafe, 
blind, or (hade, for fig. 3, for (hading or darkening the 
light when required. A is a fmall bolt or pin, made to 
pull up and puih down, and to bolt into tube B, for the 
purpofe of faftening door C when (hut. D is a ring, 
knob, Sec. by which the lamp or lantern is turned when 
put or placed in the blind or (hade, figs. 4 and 5, for the 
purpofe of (hading the light and preferving the glafs. Fig, 
3, when put or placed in figs. 4 and 5, is united or made 
("aft thereto by a hafp, or other proper faftening, fixed or 
attached in the ufual way to the top of the cafe. E is a 
fmall tube or hole to receive the catch or contrivance A, 
in fig. 6, for the purpofe of faftening or uniting fig. 3 to 
fig. 4. In this cafe a common barrel is ufed therewith, for 
the convenience of turning the lamp or lantern round 
by the barrel in the cafe, (hade, or blind. Fig. 4 repre¬ 
fents part of a cafe, (hade, or blind, which may be either 
united to fig. 5, or to a common barrel, as before de¬ 
feribed. Fig. 4 may alfo be made to turn round on the 
outfide of the circular lamp or lantern if required; in 
that cafe the lamp or lantern may be attached or fixed 
to the carriage in the ufual way, and an aperture or open¬ 
ing made in a cafe, blind, or (hade, of fnfficient length 
and width to admit the faftening of the lamp or lantern, 
fo that the cafe may freely turn round backwards and for¬ 
wards when the lamp or lantern is wanted to be dark- 
H h eucd 
