The star of the north. [volume] (Bloomsburg, Pa.) 1849-1866, 1858-01-06
Science aAd the Mechanic Arts.

Al wv toSuiotbS Vi sho supply W SoS "
burners, an apparatus is in use in England,
consisting Of cast iron vessel, with inlet
and outlet passages, tor the admission and
emission of the gas. The inIe, passage il
covered by valve, the edge of which dps
into groove containing mercury, rendering
it perfectly gas tight, without impeding the
motion of The valve, which moves with the
slightest pressure. Il is attached by rod TO
short cylinder, the lower par, Of which 10
open, and also dips into mercury. This cyl
inder covers and surrounds The inlet, and, as
the gas flows through il, exesls an upward
pressure, which adjusts the supply. If the
pressure is increased, The cy hinder rises and
closes the valve; and, as the gas is consumed.
the cylinder falls and opens the vale. In an
olhes arrangement, the regulation is effected
by Glide, or disc valve, formed by two cor
responding surfaces, placed together between
The inlet from the man and the outlet to The
puners. me supply IS Increased or u,um-
ished by the continuous opening and closing
OF The passages in this valve, which move
ments are effected by the variable pressure
of the gas within small gasomeler, which,
as 1t is greater or less, increases or diminish.
es the area Of the supply passages, and thus
regulates The supply 10 the burners.
One OF the most ingenious machines for
dove-taiing is that invenled by Mr.. BurIey,
of Boston. The main features of lhe ma
chine are platform upon which sliding
table rests, aud four circular saws, which cut
the entire pins and doveiails--doing away
with The necessity Of chiseis, and performing
the work in manner which cannot be done
by hand. The dovetailing process, as is well
known, has always been most tedious and
difficult task. Every joint had to be sccura-
tely marked out, and out with chissl by the
hand; aud in making the drawers Of bureaus
and other case-work, The expense has been
very great. By this machine, seysnIy i've TO
huudred drawers can hfTsgsay, subs,an.i-
ally and Handsomely dovsg- .iled in an hour.
The machine cuts the mortise with a sarecis-
ion and accuracy that renders every JOINT
perfect. There is also q machine working
on the same principle, designed for box dove.
failing, tho main advantages Of which are,
that the operator can dove.tail from eighty
10 ore hundred boxes in an hour--all kinds
of wood, whether clear or Otherwise, being
worked with equal facility. Hoops and nails
il all kinds Of boxes, however large, are
dispensed With, BY this method of mannfsc-
ture.
STARs-The ifreguiWiiy with which the
STARS are distributed over the celestial sphere
lie one of the mos, peculiar facts in connec-
lion with the constitution of the asiron omical
universe. 10 some regions, spaces OF consid-
cradle magnitude occur, in which scarcely
single star is 10 be seen, while in others they
are crowded together, so as 10 present 10 the
unassisied eye the appearance OF confused
mass of light. A great and repid Increase
in number is in general perceplible as we
approach The borders Of tho ''milky way"
where they appear, when viewed through
powerful telescope, to be crowded almos,
beyond imagination. Besides The general
increase which takes place towards this re.
gion, there are in several parts Of the heav-
ems patches or clusters of stars, where great
numbers are condensed INTO . very narrow
sapce. A telescope turned upon the Pei-
AIDES show fifty or sixty large Stars crowded
together within small area, and compare.
lively insu lated from The rest of the heavens.
There are many clusters which, II is thought
by astronomers, must contain a. least ten or
twenty thousand stars compressed and wede.
ed together in round space, whose angular
diameter does not exceed eight or ten miu-
u,es--thai 10, in an area not exceeding the
tenth part Of that covered by The moon.
SrEAs BoiLRns "A mode Of construction
in lhe case Of stationary engines is proposed
The vertical fsws being made Of a peculiar
form, with The ffe.box at the bottom Oft,
and with double chimney so as TO contain
water between The inner and ouIer plates Of
the chimney, 10 be heated before passing
into the boiler. One of the boilers is fixed
upon cast iron bracket or support, about
twelve inches ia height. The sides Of tho
bViler are enheicy cylindricalor coaical, the for