The sun., 1894-10-21
xoTrs ON scIEsoE AND IxDUsrnr.

Il
4 ly fine fibre, combined with a degree OF lustre
| superior TO that charscterizing short staple
| wools; OF late years, however, cameis' hair has
been resorted 10 a. substitute for this purpose,
| 4 typical vicuna cloth, "a now made, Is COM
| posed Of about twenty-five skeins OF yarn IN both
! picks per inch, the weave being cashmere twilli
such cloths. which are designed for coatinEs ana
| jecketings are not submitted to lengthy
| routine OF finishing, but are simply secured aud
tentered, slightly milled, brushed, cut not toY9
close, pressed, and steamed Among the special
requirements in treating thi:, material are extra
care IN the operations Of milling and cntilnk;
| firm, and compact.
| According TO wiedemann's Anndlen the
difficulty heretofore experienced in photo
graphing the spectrum OF lightning, namely,
| directing the slit OF the spectroscope upon the
fash. may be overcome by substituting diffrac-
tion grating for the prism; that Is, grating
| ruled on glass Is placed In front Of the object
glass Of the apparatus the object glass being
| focused for infinite distances, under these
| circumstances several images Of the Hash being
obtained, central image produced by the un,,
| diHracted rays, and images OF the irst AND
higher orders belonging. TO the dinracuon
order corresponding to the number of lines
In the spectrum Of the lightning. In testing
ing night thunder storm, two plates were ex-
| posed In a camera with a landscape lens OF ten
| en- focal leRgth, provided with a grating hav.
ing forty lines TO the MN. The result was that
| one of the plates showed two flashes with their
diffraction images OF the first order but repre-
senting one line only. The other showed = num-
Der OF flashes one very strong one. passinE np-
parently between two chimney pots, with It's
attraction images well marked.
Among the various ingenious mechanisms In
the Coast Survey Department, Washington, are
two metres and two Kilograms. the latter Of cyl
indrical form and wonderfully heavy for their
| size, inasmuch as their density is three times
that of brass, they being Of platinum with an
alloy of iridium, the last named metal possess
ing the quality of non-corrosiveness; each OF the
kilograms Is covered by two bell glasses ana
crystal In order that no dust may touch IL;
Both metres and Kilograms are composed
With sa ApsS pss Gt CENT %s Ssn Of ana
manufactured in nearly the same way. For the
proportion mentioned was finely powdered, made
into cake heated red hot, melted In lime
rolled TO between steei
cylinders. melted again, cast In, pig tngot,
eS Fsa SeG ba INTO sry . eynaer
each Of these being exactlya kilogram In weight
without che slightest possible ysriston IN fact
rubbing down TO reduce them TO exactness was
performed with the bare hand, lest any coarser
material than the skin should rub of too much.
Some comparisons Of an important practical
character, IN their bearing upon engineering
construction, have recently been made by Prof
lnurStOn. fTOu tutSc IL hppthEs tuub Chst-hOh
weighs 444 pounds to the cubic foot, and an
inch square bar will sustain weight Of 16,5o0
pounds: bronze. weight 5e5 pounds, with ten
acity OF $4,000; wrought iron, weight 4s0
pounds, with tenaclty Of SO. 600; hard struck"
$4,000; aluminium, weight 1913 pounds, tenacity
10000. singular enough, II equal weights OF
several varieties of wood are stouter than ordi-
nary steel Thus bar OF pine Just as heavy nn as
s@nars Sr no viii hold ap is5 600 bounds % the best
ash l75000, and some hernlock 100000, but the
s Se e wsa is mae ae the
United States navy is given as from $4,000 to
$4,000 pounds to the SQUARE inch BY solidify.
that tensile strength has been reached.
Accounts are given Of a new and beautiful
material for coloring fabrics, dyeing tannin-
antimony mordanted cotton q turquoise shade
u very Rreenish bue-and represented to be fast
TO light alkales. and acids; the fastness to
washing, even with strong alkalies, is also said
To be excellent, the color going slowly on to the
fibre and dyeing level without difficulty; On
shades Of great 6rilliancy are obtained-in cot
ton printing, likewise, the turquoise blue Is dis
In this connection the quantity OF tannin en-
poyed affects the shade OF the color In so far as
that, IL a small amount of tannin be taken, the
shades are bluer, while larger amount pro-
duces greener shades; the fsstness OF the color
lake IL, however, increased by the addition OF
larger quantities OF tannin.
A series OF exhaustive experiments, as pub
lished in the engineering Journals, has been
made TO determine the value of different fuels
compared with crude petroleum, and the follow
ing results are recorded: Coke that has about 9A
per cent. Of carbon is found TO contain 3,o40
heat units, requires nearly eleven pounds of air
for complete combustion, the rise in tempera-
ture being 4.s77 degrees. T.. and the maximum
amount OF water that II Will evapOrnte IL l4.l2
pounds for each pound of coke. A good
grade of bitunnous coal. containing more than
Units ' requires S " II pounds OF air for complete
combustion, the rise In temperature Is 1850
degrees. T., and the maximum amount Of
however, being an exceptional case. Illuminat,
ing gas, OF 6l per cent carbon. contains go 500
heat units, requiring nearly sixteen pounds OF
air for the combustion OF each pound Of gas, tho
rise in temperature is 4.o87 degrees, and each
pounds OF water. Oak wood, when kiln dried,
contains about so per cent. OF carbon. has 7,7l3
times its own weight of air for its combustion,
giving a rise In, temperature OF 4,2sI degrees,
OF water Wet and green sawdust, containing
IL per cent. OF wood and 55 per cent. OF moist
Temperature OF a,245 degrees, and will evapo,
rate four pounds q water for each pound of
wood in the fuel, though for each pound AS IL
stands-wet and dry together-it is much less.
II Is claimed that the treatment Of some OF the
vegetable textile fibres is rendered much more
scutcher, recently invented. Mainly, there are
four revolving beaters arranged two each
side of the machine, the members of each pair
revolving in opposite directions and on the top
of the machine two ribbon band saws.
arranged witE their teeth upward and travel
ling continuously along the sides and around the
ends OF the machine. 4 wisp OF flax IL taken
and its middle laid across the saws-One end
protects over a heater drum and Is well beaten
on one side as II Is carried along by the travel Of
the saws When the middle Of The machine is
reached ingenl0usly arranged guides transfer
the dependent ends Of the bundle OF hbres to the
other beater, revolving In the opposite direction,
by which that end uf the wisp Is beaten: and at
the end OF tho machine the bundle Is detached
from the saw teeth and transferred by hand 10
the other side OF the machine where the Part OF
the bundle hitherto untouched goes through
similar process.
The extent and power OF machinery construc-
tion are perhaps nowhere more wonderfully ex-
hibited than in the working equipment OF the
latest Government cruiser. There are sixty-one
separate engines, not counting cylindeFs which