The sun. [volume] (New York [N.Y.]) 1833-1916, 1894-04-29
SoyEs ON SCIENCE AVID IxDUs1Rn


been provi led In the construction ofths reser.
voirs when supply Denver and Omaha with
water Is highly spoken Of. The buttom OF the
reservoir is m nde TO form several large pockets
at the lowest points. in which are located blow.
OF valves. and through these water, or sedl.
mont of any description that MAY have col.
lected. IL discharged TO any convenient point
and are operated from small hydraulic cylins
dcrs over thcm, the vnlve stems In each case
heing combinations Of the piston rods worked
from the cylin ere. Water under pressure
r. supplied underneath the pstons By
pipes tunning along the reservoir ted and
the cylinders, ard ristons are 80 proportIonei
for the availah pressure that, when the water
ton Is sufficient TO raise the biow.oif valves
from their seats and allow the ercape OF water
and mud from the reservoir From each OF the
blow:off valve openings there t. a = -lnch rine
running down vertically some is feet connect
Ing with the main discharge pine. the opera
tlon being at once simple and comDlete.
In the Journal de Ni,7ondphie Dr. Van
Herrck has announced that Zeiss. working
from the formula OF Prof Able. has succeeded
in his interesting attempts to produce = Q. l.
inch npochromatic" objective with an aper.
ture Of l.G3. the same being also so construct
ed that. under suitable conditions. the whole
o. this aperture can be utilized. The interest
ina statement ia likewise made by pr Van
Huerck that with this objective he has re-
peliucida." and, not merely into lines. but into
pearls as distinct ns he has ever seen on
"pleuroslgma anguatum." Repeated meas
urcmeEts show these pearls to TO arranged
In lines according tn the lnlnitesimal meas
scopy-sernrated lonRItudlnallY by one Ave-
thousandth part ot m!llimetre, while the
ssTiff"nI are ey .he
oVOoO1 and OOOOOl4 inch respectively
A comparison OF the cost OF transmitting
power by various methods. as given in .
French mining journal. presents the following
data: ]. Comparative cost on. ton horse power
transmitted in 1908 yards-by cables, LII
rer effective horse power Der hour; By cleo
tricity. 22l. hy hydraulics, 200: By COM
pressed air. 2.oS. .. Comparative cost on fifty
horse power transmitted 1903 yards-by ca-
bles. l.35 per effective horse power per hour:
by hydraulics. 1877: by electricity. 2.o7: bv
compressed air. 2.:st X Comparative cost on
ten effective horse power transmitted 5.4',5
yards-by electricity. 2D4 per effective horse
sesSs pr GG BY Ss W b,
s1'f GSss ssrssb horse ps
hour; ~ cables 2,5 ey eomprssssd air 2gS
and il appears that. for long distance eisc:
tricty takes the lead In economy over all
with which the power may no subdivided. and
eoe MINING ssctrcty vii I9" be much much 10 n.ed ios
coal cutting. tunnelline. pun ping hauling &c.
For the protection Of sheet-iron pipes from
rust tarring lie now largely resorted to. as .
method alike simple. economical. and effeo.
tive. The sections. as made. are for this pur-
pose coated with coal tar. and then filled with
light wood shavings and the latter set on IRE.
the effect Of this treatment 1t seems. being to
render the iron practically proof against rust
for an ideanite period. and rendering future
MI l.. H.. -
this. the instance 10 cited of chimney OF sheet
iron erected in 1885, which. through being
subjected to the treatment In question. 10
brlRh; and SOUND to-day as when erected.
4 since. 1t Is suggested that by strong.
liza heating the u, iISs si.e5 the , tar
ing the pores and rendering It rust proof. in 4
be first made hot and applied to cold iron. ao-
cording to the usual practice pursued. 1t 10 .
out this method with iron pipes not only that
the iron should not he made too hot. but that
lest the tar be burned on: and hence the de:
sirableness OF using light shayings instead OF
any other means OF heating.
An improvised horizontal boring machine 10
beinR introduced. differing from the best pat
terms OF lathes In that II may be used with any
kind OF boring bar that may be preferred.
either with fixed cutter OF with sliding head.
ono OF tue FORMER D6lnR tnAt IL Se-
mains always at the same distance from the
naming therefore moro ncarly constant dur
Ing the boring. 1t Is superior for such work.
as the spindles are adjustable vertically to-
gether. thus avoiding the necessity OF block.
ing up" on the carriage and at the same time
the particular job in hand. and an sdjusts-
6ls paten o on ne ss.rage oy which the w9ss
bar aftsr being fasaaned po he nIsise W TIA
Rs:s'' gR' I Dor. siiinf IA. tn; S'n!5
travel OF the carriage. the lateral. and
vertical Adjustments needed being made az
in the same manner as the ordinary engine
lathe. provision being made for keeping the
the spindles are moved up or down: this verti-
cal movement OF the, spindles taking place 81.
multaneously. and adjustment being provided
for correcting any error which may arise
For manufacturing illtering material Q proc
ess Is described which consists essentially In
reducing ferrlc oxide by heating It In contact
with Gsseou fuel. Small pieces OF iron ore.
preferably hematite. are packed into q retort
heated externally. by means Of producer gas.
and. when the charge is at cherry red heat
gaseous fuel 10 admitted into the retort and
brought In, into mos, ihorOSgh contact with the
exit gas DO in1ammable, the process Il IN:
ishcd. and the charge raked out and allowed
fuel. may be made use Of Instead Of produesr
gas; and the retorts may be osoillAted. rocked
I le produced in this manner Is available for
altering water. sewage, sugar syrups &c.
The use OF oil in preventing boiler scale
now so prevalent, Ia met with the objection
that in using other than standard oil OF $50
TO 800 degrees IRE test. there 10 danger OF the
formation OF what Is called oil scale. This. Ae-
cordinR TO chemical authority. is owing to the