Weekly national intelligencer. [volume] (Washington [D.C.]) 1841-1869, 1857-03-28
SCIENCE, ART, AND MECHANICS.
Written and compiled for the National IntslligsseA.1

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treating lead by of common SALT or its chem
cal equivalent and sulphuric acid has been proposed
BY Mr.. ]. E. schwabe, and appears to possess some
special merits One hundred pounds of powdered caena
ore arctic be mixed with fifty pounds of common rock
SALT and to this added from thrtyseven to forty
pounds of an acid of IS degs. Beaume The decompo
sion begins the chlorohydrc acid formed by the
on of the acid the rock SALT drives off the SULPHUR
the suphuretted hydrogen and unites with the
lead to form chloride of lead Small quantities of water
may be added from time to time and under continual
stirring and moderate heat the operation is continued
till no more evolution of suphureed hydrogen is per-
ceptible Then more water is to be added till about
gallon OF water is added for every pounds of
1t then to be boiled for about fifteen minutes and the
nsoluble mass allowed to settle The LIQUOR is then
drawn off and the transferred to yats in which the
soluble soda is completely washed out The remaining
nsouble whsh substance consists of more or eho
ride and suphate of lead and contains generally some
ndecomposed ore, which may be separated by washing
The white salts of lead then ready for further treat
men varying according the colors which are intended
| to be made.
| MACHINES FOR FoRGING CAR WHEELs-An improve
ment has been made in machines for forging car wheels
1t consists in making the face of the hammerdie with
series of flutes swels extending from near the bub
towards the rim in curved lines or in lines tangent to
circle of less diameter than the rim of the wheel
when this is employed in combination with the turning
between each two bowsof the anvil or the hammer-de
portion of revolution about equal to half of the space
between the flutes that the next blow the ridges of
the die will strike the ridges formed on the block of
iron by the cavities of the hammerdie by the previous
blow. These are the to facilitate the spreading
of the metal towards the periphery of the ebox to form
a thoroughly compacted tread and fange.
New USE FOR STEAM-m Scotland it is proposed to
fit out steamers instead of ships engage in the whale
trade 1t but three four years since the bomb has
been in use; this much trouble and many lives
After the harpoons and lines attached to him
the whale is fatally wounded if not literally blown to
pieces by the explosion of gunpowder in the deep wound
made by the lance Now it is proposed to employ steam
in the pursuit. which it is thought will pay largely as SO
much of the surface of the ocean can be in
quest of them, and when perceived they will rarely
escape
PRoF. FARADAr ON THE AURORA Observation-Disclosures
Faraday is of the opinion that the aurora NAV be l
minous representation of electricity flowing from the
equator to the poles for the restoration of electric eou
librium. There also to be some eonnexon be-
tween the magnetic poles and the aurora having been
observed in Europe that the elevated point of the
is always situated in the magnetic meridian of
the place of the observer. 1t is likewise inferred that it
has relation with the temperature of the atmos
pheric strata in which is produced The fact that the
can be initiated by passing electricity through
vacuum, causing beautiful streams of light which vary
in color and intensity according to the amount of air
present. would seem to imply origin.
THEORY OF THE EARTH's CREAT1oN-Thomhs Burnet
the author of work in 1851 entitled The Sacred
tba Earth
the beginning fluid mass, consisting of all the va
rees of matter The heaviest descended by their gra
witty to the centre and there formed solid nucleus
round which the waters became first united and then
the atmosphere But between the water and the air there
formed oily layer, which received by degrees all
the earthly particles with which the atmosphere was still
charged and this became Solid uniform and level with
cut mountains, valleys, seas rivers but yet very fer
tile, and so continued for sixteen centuries from Adam
ID the deluge. At that period, however the crust of
clay dried by the heat of the sum- cracked and fell into
the great abyss of the waters Hence came the uniyer
sal deuge the arrangement of the axis of the globe and
the change of climate; and hence also the islands
continents, and mountains
BOILER ExPLosIoNs.-Mr. Ward an eminent practical
mechanician connected with the Novelty Works. New
York, has given it his opinion that some of the pro-
posed devices for the prevention of boiler explosions are
all likely to accomplish that intention and that
the idea of rendering any boiler safe by placing any APP
paratus whatever to the outside of the boiler and even
placing detective machinery Within is entirely falacious
Whether the continuance be usbe metal plates or plugs
floats steamwhises, any indefinite increase of
the number of safety valves the most elaborate modi
cations of feeding pumps of these postpone the
bursting of boiler prevent the rupture of the metal
when subjected by the pressure of steam to strain
/ l,al, tbo ,1t,r
should be borne in mind that this limit in
whether used not is daily and hourly diminishing
The best known for essenng the danger of explo
sion, which is an inevitable attendant upon the use of
all boilers subjected to pressure of steam are first
to good materials and workmanship and second
confidence in the integrity intelligence practical skill
and sound judgment those entrusted with their manage
ment When these wanting no boiler can be worked
safely.
MANUFACTURE OF PATENT LEATHER.-The process fol-
skim with appropriate TOOLS three four successive coat
ingsof drying yarnsh made by boiling nseed oil with
white lead and harge, in proportion of one pound of
each of the latter to gallon of the former and add
ing portion of chalk ochre each coating being tho
roughly dried before the application of the next Ivory
thinned ,sith spirits ~ turpens and Eve
additional applications made in the manner as
FORE except that it is put thin and not worked in
The leather is rubbed down with POWDER
and then placed in ninety degrees out of the