The sun. [volume] (New York [N.Y.]) 1833-1916, 1897-06-06
oN SCIENCE AVID rNDrsrxr

The sewage Of the largest city In the world, Ton
don. IL nand!"d by two main pumotag stations %
each side OF the Thames. with machlne.y o; an az.
Ercsate of s.ooo.horse 20 ser. capable OF pumping
some I'VE hundred million gallons per day. and .
like number OF storm-water pumping stations. ca
pabie Of pumpirs directly into the river $50. ooos-
600 gallons per day-the latter being used for pre-
venting flooding In the lower parts OF the metrop-
oils when . heavy falt Of rain occurred at or about
the Tine OF hish water, when the storm outlets
we're ciossd by the tidsl water. The outrsrl WORM
for the publication of the sewage. the dry.weather e
now Of this exceeding 200, 900. 900 saiionsper day.
consists of settling tanks and their accessories for
the chemical treatment OF the sewage. and the
means for removing the siufre produced 20 the
German Ocean. Tho tanks At Parking are rated %
10000, 900 gallons. and those at crosSness at ST.
o $1,000, the sludse. amounting to more than 2.oo0,.
900 tons, being discharged into the open sea at .
distance OF about nifty miles from the WORKS BY . d.
neot Of steamers. We s.
The largest nuuie In the world 10 claimed for San
Diego. Cal In the course OF this remarkable wcre
there are ais trcstIes. the most notable of which
Is 1900 feet in length and IS feet htsh. knoEns
a. the Los cochos trestle. It's construction requir-
ing $4,000 feet OF tumber. Then there is ne
sweetwater trestie. 300 feet long ana 80 fees
slsh-the vain ttnbers used in these tresties being
ten oy ten and etgat by eight, put together on The
ground ana raised TO their position BY horse power.
There are eight tunnels In the course of the nume,
the longest Of which Il e.Iuo feet. the sire or the
tunnels being SIX by six feet, with CONVEX shaped
roofing. Each mile OF tts flame required. on an
average. $50. 900 feet OF lumber for It's .construc, ,
tion. and the REDWOOD used In the box IL ali two
inches thick. The grade OF every mile was engt.
neered with such care n to insure the utmost pre-
cision in that respect, . uniformity being secured =.
OF four and seven. tenths feet othe mtie. Il isen-.
pectsd that before long the water from hits greco
nume will be flowing into the city Of San Diego. .
A writer IN the columns OF Inventfon. q London
publication. describes the new system OF oil light.
ing by constant supply. Introduced in that clty-a
system which pinces paraf1n oil.users on the same
footing with regard to supply as gas consumrts.
The main oil supply tank 10 located ir any safe pc-
siiion IN the upper part Of the house. such as In .
store cupboard or attic or it may be outside the
building against the wall. and pipes lead from rhe
tank to the various nttings. Interposed between the I
tank and the burners Is q feed governor. which reg
ulates the amount Of oil, prevents any chance, % -
overflow. and crectualiy cuts or the liquid when =
the burners are exfinguished. The Light is OBJ .
tanned by consuming the oil by means OF a wick.
and tho burners are similar to lamp burners,
though. instead OF being attached TO the lamp or
reservoir they arc screwed to small cups. only
large enough to hold 'he spare wick. These cups'a are
attached TO the ends OF the arms OF the Chandeliers "
or brackets. and the wtcfs are Kept saturated with d"
the on. which flows through tubes In the arms. me
feed governor is perfectly selr+acting and requires
no Attention-placed in q sealed box. to prevent be-
II "ibhs III u iV-u
or is fitted tn the central ornament of the ntttus. /.
but in brackets It is in 3 separate box. One faeA I
Will work any number OF brackets on the. sane
level. and # gives on the oil drop by drop where
one burner only II lighted, or In a full flow whereA .
number Is burning.
The fact that wood rapidly oxidises at certain So
high temperatures ana becomes infamed is well at
tested. The wood tagging which encircles locomo-
tive ooilers has frequently been found TO have been
burnt to coke. and in some instances has actually
taken IRE on removing the outer casing. Here the Z
temperature would not DO over 500 r. md though
the heat would not of itself be sunicient 70 tgni.e
wood. rapid oxidation at such q temperature muss
soon bring about sufficient heat to cause ignition.
The temperature At which wood takes IRE " com.
puted ct 900 to 500 degrees F. The more oleaSi-.
nous or resinous matter the wood contains the
greater its susceptibility to Inflammation. AMI this
fact IL to ID made account OF In all calculations.
For some time past experiments have been made
BY. engineering experts at Poplar. England. to as
certain the effect OF feeding one of the ~elkknown
Yarrow boilers with salt water. This boiler. as 10
familiar TO all engineers. is OF the express or small
tube type. having tubes about vne and one =eixhth
inch diameter. a compared TO the four and one.half
or nveinch tuoes OF the type Of water tube bvilera .
now being introduced for battle ships and large
cruisers. It has been considered. It seems. that the
smaller tubes of the express boiler would be quick
iy stopped up In case salt water should gain access
TO them through Q leaky condenser or other con-
tingencies which must be provided against. Now.
the important point OF Information has been
gained by these experiments which disproves such
n theory: that is. the successful running OF a boiler
of this description for some time. using only YEA
water with a sreater de~nsry-that is. Q larger pro-
portion of lait and other mineral constituents
than would have been considered suitable even
with the ordinary shell boIlerA. In other similar.
experiments. favorable results are reported: tho
boiler was continuously blown on. the Adjustment
being such as to maintain the water In the boiler. At
& density OF s. 81. or three times the Density OF sea
water. The difnculty anticipated IN using sueh
water was not only from incrustation OF tubes. bus
from printing: no dimculsy. however. arose from
either of these.
Floods along the Mississippi. so prominent q pho
nomenon OF late. have led to some interesting cal
culations by John Birkinbine of Philadelphia a.
to the watershed OF that great river. His ngures
show that its drainage area Is one and one. fourth
millions OF square miles, Including nearly all OF
the country from the AIsEhanies TO the Rockies,
| anu from Canada to the Gulf OF Mexico. In his
communication on THIS sub tect TO the Ergfneers'
Club. Mr.. BirkinoIne estimates that one inch oil"
rain railing evenly over this vast area would bs
equal to FL $50. 600. QUO. 900 gallons OF water, this
vast flood having to IND It's way to the ocean By
way OF the river. aud the quantity Of water from
this not immoderate rainfall would be sufficient 70
supply Philadelphia al tho present rate of con-
sumption for S2S years. A q matter OF fact. the
average yearly fall In tho Mississippi watershed
averages from twenty 20 forty-three inches, &C.
cordinE to the locality. The river has an average
now OF $4,000 cubic feet per second. and II this
were put under a head OF nifty feet IT would do.
velop 1900. 900 horse power.
Ono OF the latest novelties In the field OF shes r.
metal working as noticed in the Metal Worker,
and produced by a nrm In ST. Louis. No. name nos
given-is that of steel sheets coated wiki alumni
mum. these. It Is claimed, being superior to and
more durable than galvanized iron. tin plate. or
planished iron Ter many purposes for which those
materials are now generally used. The special ad-
vantaRes of such aluninum-coated sheets are stat
ed 70 be that they can be worked and scanned with.
out psslins. the coating. adhering absolutely TO the
sheet. can be easily soIdersd. will resist the action
II sulphurous gases. and can be heated TO . red heaS
without destroying the coating. Moreover. such
sheets eau. when desired, be polished to q lustrs
equal TO Furnished silver or nickel. An absolutely