The sun. [volume] (New York [N.Y.]) 1833-1916, 1899-08-27
NorEs ON SCIENCE AND INDUSTRY.

scientific examination Of the matter based upon the
beet opportunities OF judgment. have more and more
led to conclusions unfavorabe to the employment OF
the electric for lighthouse purposes-that, in
clear weather, other lighthouse illuminants
ply sufficient in power and the electric light ia very
apt to msleSd the navigator to his distance from
the light, whilst in hazy foggy weather. repeated
observations alike by mariners and scientific men
have shown the inehicency OF the new light, Of
the most powerful description, and in lighthouse
OF the first order. though this II Ia admitted may be
due In part TO the fact that Of high rerangibi
ity, such emitted by the light in question. Nre
moro largely absorbed by fog than rays OF lower
refrangibility that emitted by oil gas Another
ana moro potent cause. In the estimation Of this
writer lies in the very condition which gives the
light Its great value for optical namely, It's
centraon In minute area compared with oil or gas
but regarded a. positive disndvantage for light
house illumnant in foggy weather.
In the beautiful art OF transferring copper print
pictures to wood. the most satisfactory results says
the Mailer Zeitunp. obtained by . simple process
with poplar. linden, MAPLE or other kinds Of soft
wood. the surface being nrst rubbed smooth with
bleached nnseed oil and warmed over coal nro: this
10 followed by coating the surface three times with
varnish made Of thirty grams sandarach, fifteen
grams shellac. the same Of turpentine. and
a75 grams OF 90 per cent. alcohol This
varnish may be colored as desired, that 10, red
with dragons blood. or yellow with curcuma. The
copper print Ia now soaked thoroughly in salt
water. thon laid on plotting paper. so that the
moisture Ia drawn or and the picture remains only
damp; the wooden surface Ia next again coated with
varnish, likewise the print the latter being placed on
the wood with the printed side down; then the artist
lays upon this piece OF flannel. and the latter
smooth, warmed piece of wood, aud squeezes the
whole firmly together in screw clamp. After few
hours the work being dry. the back OF the paper 10
carefully fubbed of with linen rag saturated with
WATER finally. the transferred picture 10 rubbed
lightly with nsocd oil and coated few more times
with the varnish.
An elective leather cutting device invented by
Henry Parsons of Marlboro, Mass, is claimed to
solve the pro lem how to arrange for the continual
moving OF the dies on the block other than by the
hands Of the man operating the machine; the dies
weighing from ten to twelve pounds. many
changes were necessary during the day. work being
thus made slow. BY this improved arrangement, all
such movements are superseded all that the opera
tor has to do being to change the dies when
sa,y and do the cutting easily he operates his
machine. On the beam OF the sole leather cutter 10
an iron carriage extending from which is arm.
attached to the latter being two spindles and at the
end of these is magnetized hand-ike fixture.
which firmly holds the die.this receiving it's power
from tiny electrical dynamo arranged at a conven-
lent point the ceiling Of the room. and transmit
ting its power t. the clasp below The invisible
power In question firmly and securely holds the die
the easiest and most pliable motion that be
desired.
II would appear that the grest Manchester Ding
land canal has disadvantage while at its vast
and splendid docks may be the fulhlmen of its
purpose IN extending the facilities Of foreign COM
merce with that cty.-steamships now being seen
there from Russia. Halifax. India. Sweden. London.
Italy. and elsewhere.an unfortunate defect 10 the
disooloraton Of the water and an accompanying Of
ndn l,,ig into naaI
by the refuse and offal from dye and chemical es-
Establishments, coming down from the upper river
end Attempts have been made to prevent this I'M
sanitary condition OF things but thus far without
avail, by ancient right the mills continue nse
the narrow river for sewage purposes. There has
for sometime past howrvcr. been a stupendous
scheme foot for sewage system which 10 to
carry away to the sea Manchester's refuse. II 10
found that the great dredgers. at work day and
night. can do but comparatively little against such
contamination. and. above ALL the sanitary require
ments of the city imperatively call for action.
M Louis Boutan. who ia connected with the Arago
laboratory at Bagnuls the seacoast has recently
presented to the French Academy OF Sciences valu-
able sercs of instantaneous submarine Photographic
taken with camera eighteen by twenty-four cent?
metres, having an anastigmatic objective and ar
ranged to be operated under water These plates
said to have been obtained q clear day when
the sun was high in the horizon. tho results being
quite satsfaotory TACT, several OF the plates
are clearly perceived bands OF hsh which had been
taken at distance OF l.5O to two metres from the
objective. the camera being immersed to a depth Of
three metres. In order to form q background, Q
white screen was let down. and before this, bait was
thrown down in order to attract the fsh into tho
field Of the camera. this however being represented
not Indispensable certain OF the plates the fish.
being easily distinguished against the sandy bottom.
and diver placed against = background OF seaweed.
at q depth of three metres and Il distance of four
metres from the camera, gave a very good image.
tits we'll know that great deal OF effort has been
put forth in all parts OF the world where mining 10
carried to . great depth to determine as q salts
factory average the increase of the earths tempera-
ture with depth. few years ago II was commonly
assumed to be 10 for each ninety feet in depth.
but moro recently. deeper workings under other
conditions have led to the belief that 1t Ia something
two hundred feet for each degree OF increased
temperature. It 10 admitted however, that the depth
to which mining has thus far been carried Is SO
shallow. a. compared with the great distance to the
centre OF the earth. that II is really not known what
the average increase of temperature with depth ia.
Observations made at the various places have been
where the surrounding conditions were so different
that the tests satisfactory a. example,
those made in the Lake Superior and Nevada regions
A peculiar and little known industry, viz. tho
incrustation Of precious woods with pearl
an entire street. known an the street OF the in
layers is devoted to this delicate art 90 perfect
Is the skill displayed In its elaboration that land.
acapes cleaning in the sun. sheAfs OF many-colored
| flowers, the most exquisite arabesques and various
other attractive objects evolved by the deft and
plant fingers Of the artihcers all this with the aid
only Of the plainest and crudest tools. beautiful
cabinets and other articles being thus fashioned and
put together without the aid OF nails by dovetin9
and lacquer paste In this connection may be mem
toned the new German stone wood" or Iyloth. .
compound Of sawdust and magnesia. treated so to
become harder than granite it can he worked with
tools. but 10 OF such nature that 1t will neither
/ burn. warp nor absorb moisture the material 70
produced under 4 pressure of $50 atmosp heres.
may be OF various colors and patterns. and can he
moulded into plates for tho table wAinscotng steps
| for stArways. &C.
Some interesting figures were recently given in
LEelaird0, EieetriQus by NJ. WITT. showing the
great waste Of energy which accompanies the loss Of
blast furnace gas Furnaces OF 100 TO 200
l