Fort Worth daily gazette. (Fort Worth, Tex.) 1882-1891, 1888-04-12
POPULAR SCIENCE.
Items OF Interests to Artisans, 1o,sntists and
Mechanics

H2>uIs lssuSu Id tnlS country IN 1857.
! A recent E 1glish invention relstes {
casting packing rings ready for use viii
out boring or turning. The rings az
cast In chill mold around ametallie c3Te
Wood pGlp is rapidly being substitutes
Tor plaster OF Paris in the mspufscture O
ALI kinds OF building ornaments il
Frasce, where new method has beel
devised.
The number Of hides impoyEed into En-
gland for home consumption is estimated
st $3.50 OOO per annuM, which together
with the domestic hides bring the tots
number to about 20, O0G,e0o.
To make 81 ing for hand stamps that
will not tDjnce the rubber: NJ I and dis
solve to drains aniline color aiteer
ounces alcohol, flttesn ounces glycerine
The solution is poured on the cushion End
rubbed in with brush.
Fumigation is said to have originated
'ita AcroD. a physician of Agrigeutum,
/ who Is ssid 10 have first caused great
fres to be lighted and sromstics 10 be
| thrown into them TO purify the air, AID
thus to have stopped tue plague at Athens
and other places IN Greece about 473
8. G.
at the general meeting OF the American
Gsslight Association, DR.. Morton, the
! well-kno~n physicist, warned people
sgainst the use Of unscreened electric
| and gssliglts. Lights should be piscad
above the visual range and shcded SO as
to produce diffused and equsble light.
Good cement tor sticking porcelain let
,ets ON glass: Starch, sixty parts; finely
pulverizad chalk, 100 parts. Mix with
equal parts of water .ud slcOaOl, with
the addition OF thirty parts Of Venice tur-
peutine, taking care to agitate the mass
with stick so as 10 insure It's homegene-
ity.
The Scientific American gives the fol-
lowing method Of perforAting earthen-
ware: "A soft copper rod or pipe is
used in the lathe, 1t being fed with mix
tufe Of powdered emery and llnseed oil
The emery Is imbeded in the copper by
the friction, and cuts right through the
hardest material in very short time.n
The "opsiometer" is new instrument
for testing the eyesight. 1t consists of q
mahogany case with two front eyeholes,
behind which are two travelling bands
mounted on rollers. These bands have
holes in which different lenses are fitted,
and the person whose sight is 20 be tested
looks through the holes and lenses at
printed matter behind.
1t is q new idea to most persons that
edge-tocls not infrequently get "tired"
snd will not hold s keen edge until they
have rest. This is the testimony Of
carpenters, BARRIERS and wood choppers.
Locomotive engineers notice the came re-
suit in their engines. Possibly constant
and hard usage may cause changes in the
capitalization that would account for
Ibis peculiarly IL inaminate things.
At some recent experiments made under
the auspices OF the Ecroststic crops of the
German srmY good photographs were
taken of the surrounding region while a
balloon was poised $500 metTes-about
one and hall miles-in air. II will be
remembered thSt during previous tests CT
this kind so many difficulties were met
that the promise Of any really prac rically
valuable work seemed rather doubtful.
By means of careful records most of the
railroad companies are enabled to know
exactly the work done by every carwheel
IN the service. Some recent accidents In
New England attributed to the breaking
wheels have brought out some interest
ing information as to the life of 8 car
wheel. Upon some roads steel wheels
are expected TO run 80, 900 miles, but as
rule they are taken of before the maxi
mum Is reached.
At recent meeting of the ROYAL
Society paper on the spectrum of the
oxyhvdrcgen fame was presented by
Professors G d. Living and J. Dewar
They find that the spectrum of water ex-
Wi mi
the visible region and also far into the
ultra violet. They hsve photographed
these parts, using single c.lclte prism
and long Exposure, and give map and
a list Of wave lengths of upwards of $50
lines.
Gan automatic safety engine" burning
kerosene oil, is ssid to be all tha. its
name implies. The several parts are SO
we'll designed that 8 hot bearing has
never been known as yet. The fuel is
kerosene oil, at the exceeding low first
test of 110o to l150, which mskes cheap-
er fuel than hard coal at 81 90 per ton
These engines are aa.pted TO a great
variety OF work, from running sewing
machines to driving elevators. They viii
never fail where fair usage Is granted
them.
Tae toxic properties Of metals are In
proportion to the atomic weight and the
specific hest of the metal. The theory
may be expressed thus: The higher the
atomic weight ami the lower the specific
heat the more intense is the metallic
poison. Lithium furnishes an exception
to this law OF toxiciry Of metal; bu. me-
tslic lithium kills by its convulsing &C.
tion on the nervous system, and not by
the ordinary toxic effect of metals which
is that Of destruction of the functional
activity of the nervous system.
D.. P. Lsnge, in paper read before
the Electrical convention on chow 10
protect watches against the influence Of
magaetism," said "In my work ss sn
investigator Of this subject, which has
extended over period Of several monthe,
have iormed three separate solutions to
the problem: /. To have the watch made
of material that cannot be magnetized; 2,
to inclose the works in an iron case, 80
as to shield the vital paris Of the watch;
and 8. to apply efficient means to demsg-
netizs the watch that has not been favored
with the safeguards"