Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1898-01-27

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luiry he found that certain bricks re-
NAMED quite smooth when piled up, and
soon became covered with efilorescences
1 when used with mortar that proved
perfectly harmless to other bricks. AL
| most all clays contain pyrites, which, In
| the presence of magnesia. give rise 10
! immediate effiorescences; but In the pres
snce of lime only after decomposition with
| the alkalines OF the mortar
The making OF ships masts is one OF
| The nautical Industries which, on the score
| Of economy and strength, has undergone
| total transformation-the solid stick,
| once universal. being now universally dls-
| placed by what is termed the built-ur
mast-made, that Is, OF a number of
pieces. The primary advantage claimed
| in this case is that it overcomes the diff
| icuty of obtaining a solid stick of suit
able dimensions for q mast absolutely
| free from blemish, while In making the
| bullt-up mast-comp0sed OF a number Of
| smaller pieces-it is easily possible TO
select only perfectly sound material. The
usual method i'm this style of construc-
ton has been that Of a spindle-a big,
square timber forming the centre or heart
the round of the mast being formed by
slabs laid on the sides Of the spindle.
these parts not always being OF single
piece each Sometimes, also. the spin
dies length is composed of two or three
pieces scarved or spliced together, and
he I,l. trl.
brought opposite the scarves i'm the spin
die. The finished stick, banded with
hoops of iron. being subject to decay.
give place, necessarily. to the next i'm
proyement-tubes of iron
With a view to determining the effi-
cheney of dredging appliances in dealing
with fineiy-dividcd gold, the following
investigation was made, as reported in 4
New Zealand Journal. A sample of fine
gold from an electric company's dredges,
about two grains in weight, was sifted
through a sieve Of some 1900 holes 20 the
inch, and was again sifted through one
OF 1900 holes, and the gold which
passed through was sorted under a power
full lens. One hundred Of the smallest OF
these pieces were then selected and ex-
amined under microscope. Measured
with a micrometer, their dimensions i'm
fractions of an inch varied between
O.009x0.0O6 and 0.0O8x0.O02, the mean OF
twenty measurements being 0.0O65x0. 0042.
The hundred particles were then careful
ly weighed and found to have a mass OF
0097 of a grain-the mean weight of the
pieces being, therefore, 0O0J97. or a little
under one-thousandth of a grain. With a
moderate power only. the larger pieces
were found abraded and then but slight
ly; the smaller were not water-worn, and
one specimen was dentritic in appearance.
The finest particles were nearly equal IN
width and depth and by no means fiaky-
coming rather under the classification of
shotty gold, although well defined where
edges and angles occurred.
In calculating the management of the
smoke nuisance consumers have to deal
with some chemical factors not formerly
so well known as now. The fact is now
established that IN some Goals there is
present a notable amount Of sulphur and
hydrogen associated with their carbon.
The gaseous products of an imperfect
combustion Of such fuels contain car
bonic acid, carbonic oxide sulphurous
acid. sulphuric acid, the vapor or water,
ammonia, nitrogen, carbureted hydrogen,
of less Importance. All of these gases
and vapors escape from the chamber I'm
which the fuel is imperfectly burned at
a high temperature, upbearing and !
spreading abroad the fioCculent solid |
carbon or SCOT Most bituminous coais, |
too, when imperfectly burned produce |
smoke of substantially the above compo- |
sition. That such smoke is injurious 10 |
health, as well as to vegetation, is well
and the remedy pointed out |
consists simply in effecting the perfect |
combustion of the fuel used, and in the
use of a fuel whose complete combustion
will not produce deleterious gases.
An Improvement in the process Of Sc
parating gold and silver from the ores
has been devised by Henry Rhodes, or
Denver The preparatory method is TO
grind the gold and silver ores to the de-
sired fneness and then add certain per-
centaee of common gypsum, also reduced
TO a certain mesh. To the ground ores
and gypsum is added water. and the
thorough mixing or churning OF the pri-
NAL ingredients begins. When this mixing
or churning reduces the ore and gypsum
to the consistency of clay the matter is
taken out and moulded into any desired
form and left to dry, which requires but
a very short time. After the bricks or
slabs have become sufficiently dry they
are ready to be dumped into tanks or
other receptacles and a chemical solution
is turned on; and, the matrices being en-
tirely porous, the chemicals permeate the
bricks, carrying away in solution from
IS TO 80 per cent of all gold in the ore.
In reviewing the different methods now
In vogue for obtaining Illuminating gas
and manufacturing or fuel gas-the stwO
kinds produced from coal by means OF
the retort coke-oven system-Mr. w. g.
Irwin remarks, in Casters Magazine,
upon the great extent attained by this
industry II has been estimated, he says.
that for each ton of coke produced up
ward Of 5000 cubic feet OF gas are given
off, and the entire product yielded an
nually in the United states by the
coking of coal. allowing One-half to be
in the coking process, is up
ward OF sixty billions of cubic feet, or
but little less than one-fourth Of the an
nual national gas production at the
height of its most fiourishng period The
by-product oven tar Is superior 10 the
tar which comes from the gas-works-it
contains less pitch-the yield for each
ton of coke varying from forty to one
hundred pounds, according 10 the amount
)f volatile matter contained In the coal.
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