The daily gazette., 1879-05-08
science. Ina.ssry and M.naf.es.rs.
DRESSING STONE.

DRESSING STONE.
Various attempts have been made to
supersede the ordinary methods of work.
Ing In stone, among these being the ex-
pensiye steel cutters, made to the shape
of the molding, and fitted to powerful
machinery, the stone to be worked be-
Ing passed TO and fro under these. As
soon, however, as action is commenced
with this arrangement the tools are
found to lose their cutting edge and
grind out Of shape, with . failure to
form the molding. ..l4 l
On account, therefore, of the weak
ness Of that complicated tool an Eding-
burgh inventor has lately devised o ma
chine having simple tool, and forming
the molding by an independent motion
not affected by coming in contact with q
stone. 49,, = '-...-l ~ ..,,---''
1t was intended to operate upon the
stone by circular saw set with black
diamonds, but for this the inventor has
substituted new and cheap tool, form
ed OF a novel composition. A circular
thin saw, composed Of this new material
will be guided in its movements by
cast-iron enveloping form, working in
conjunction with suitable machinery, in
such q manner that, at the termination
Of each cut, the saw is alternately moved
or fed until the molding is completely
formed thus, holdings of all sizes and
characters are worked by one and the
same saw or tool-and, as one develop
ing form produces holdings of any size.
only one simple cast-iron form Is neces-
sary for each pattern. .n
Again, there being practically no wear
on the cast-iron developing forms, no
matter how great the quantity of mold
ings worked, there will not be the slight
est degree of variation. Another ad-
vantage obtained by forming all sizes
from one development is that the whole
of the holdings are increased or dimin-
lshed In size to q true scale, and these
developing forms may be set out so as to
produce the various members of mold
ing with care and precision, the fine
quality Of the work being thus fully as
srreds oli lai idHo.ol ..s
srpH SUBSTITUTE FOR LEATHER.
"A new chemical PRODUCE, termed leath-
eroid, and intended as substitute for
leather in many cases, has recently been
introduced. 1t is made Of two varieties,
one being soft and flexible like leather,
the other hard like gutta-percha or vul-
canlzed rubber-resembling those mater
ials IN Its density, strength and hardness
and like them, susceptible of very high
pOlish. The article Is manufactured fl ON
vegetable fibre by q peculiar chemical |
process, and formed in sheets of twelve |
teet In length by four feet in width it |
can be made Of any desired thickness.
This substance, 1t appears, has been
thoroughly tested as substitute for natu-
raj leather In the manufacture of trunks
and washers; for gutta-percha In combs,
napkin rings, ETC., for tin and iron in
rowing cans and bobbin boxes for cotton
mills for whalebone In whips for cop
per 10 shoe tips !; for wood in chair seats |
and also USED in the manufacture OF fric-
ton pulleys for machinery cams. The !
material can be made Of any color, though |
brick red, In imitation of leather or vul-
canized rubber, is commonly preferred;
black, which is used for combs and canes
and walnut, which is employed in the
making of chair seats.
OF NATURAL FORCES.
In lecture recently delivered by DR..
Siemens, ON the utilization of heat and |
ether natural forces, he explained. among
other things, how heat can be made to |
10 greater amount Of work than ever
by means of electricity. One hundred
of steam or water may be |
used for instance, at q central or convent |
ent place to drive dynamolectic ma
current there produced could,
he asserts, conducted by means of pipes,
10 halls or factories, and then be convert |
ed into light, or into mechanical power. |
II light were required the equivalent to |
one hundred and twenty-five thousand |
would be given at an expenditure
Of three and three-fourths' hundred |
weights of coal, instead of three and |
tons-at least this is the |
result as worked out by DIR. Siemens.
The amount of force which is lost from
not utilizing the falls of Niagara is, says
Prof. Siemens, enormous. Thus, every |
hour, the vast quantity of one hundred |
millions of tons of water descends, and
here height of one hundred and
fifty feet Is equal to nearly seventeen |
millions of horse power. To pump that |
water back, estimating the consumption
of coal at four pounds per horsepower
he hour. would require two hundred
and sixty-six millions OF tons of coal for
\ single year.
wRIGHTINa OF TISSUES.
The Monite1r Scientifique asserts that
t Is the common practice now to weight
,ottt0n goods with chloride OF magnes-
rm, and that from this cause, certain
'hi:tings lose, on washing, from fifteen
% forty -hyo per cent of their original
weight. The chloride ofmagnesium Is
Iold tor this purpose sometimes openly
lnder its own name, and sometimes un-
ter the more plausible trade name of
u "crystal size" The sulphate of mag
nesia or, ~ 1t is more commonly termed,
EPSON salt, is also used for the same
purpose.
Curious enough, there was offered dur
ng the past year to the Lyons silk dyers
~ article, the composition of which was
made . mystery, but which was simply
he chloride of magnesium. Silks steep
ID In this solution after dyeing Will in
.rease In weight from fifteen to twenty
per cent, but the "handle" is senslbly
and the goods become hygr0-
metric. "rl
Unfortunately SILKS are always weight
ID WITH sugar--a custom which, 1t Is al
egsd, far from diminishing, increases
more and more. The uso of Oxymuriats
3f tin In concentrated solutions az twen-
Iy-five degrees BauMe for weighting COL
pred silks, Is very much restricted by the
TACT that 1t Affects certain cOlors. On the
3ther hand weighing with sumac and
yails II extending.
The Inhabitants of South hsastern Mas