New-York tribune., 1876-04-08
APPLIED SCIENCE.

hl
v,,rvs OF Potash FERTILTzERs.-The potas-
-, :, thu German potash salts occurs elmer
:. ,otassium sulphate, "sulphate OF potash
:, az potassnm chloride 'muriate OF POTASH IL
~anerally comes at lower price per pouhu as
shloride than as suphate. But, as Prof. UoeSSiIah
orv iust,y remarks, there are other innings pcsiuo'
Ct cost 70 he considered in buying theSeenah.ics'
ING cxperience in Europe has shown that the ioiln
=; which the potassium is present as wen as '"o
or,ount and nature of the other compouh"S '"''
ocur in the German salts, cOntr0l 10 great cA''"'
their action upon various crops ana solls' Inc SUI
obate of potash is unanimously approved as
rH.ash hoomnonnd-without regard to kind OF crop
snd rs far as the quality of some of the in"uSIrlai
anoancts ara concerned 1t increases the percentage
Of starch in potatoes, and of sugar III sugar ooe''
Il counteracts best, in common with hi'ra'e Vi
notassa the tendency of tobacco 70 cn''' an" ~
smell otien.ve thereby rendering it better adap'eo
% smol,,pr. and increasing its commeTclal Naiue'
T,on wet lands alone the Sulphate is consid'rea as
,rrro6tahle and the chloride oi POTASSIUM INC SlleI
ertIcle The chloride OF potassium on Wy "tiiri ti
hand has not received sucu Et',o " d tnh"cco has
been decidedly discouraged, for IL actS Oh ltro !e
crons more IN the direction ol quantlN
~ ouaIity II is. however, Mghly recon-
,Innde3 for meadows for pasture lands anu Tor
aiI kinds of forage and gram crops, particularly
when applied in connection VII PhosP'ef f cnmo mo
rounds chiorides and sulphates Is also frequently
md i'm nm unusual degree mOdned by the presence
If certain other other saline compounds. wlcn are
9annd associated with them IN the MINES. M"s'
,ra,,;ucut among these are sodium chIOllde (com-
nmon s,l0 magnesium chloride and magnesium
snlnbate The pTesence-inoIS nan mere vs-.oI
p,ieSn,D chloride Is decidedly objectionable, for
is action on plant growth IN general Is known To pe
destructive /; favOTS, also, the transformation OF
lime in calcium chloride, and thus assists III scdlhg
IL.
Uater A large admiXtuTc of common salt-Iaome OF
these fertilizers contain from 40 TO - per cent IL
,DJers tbrm Improbable for the cultivation OF the
n,nre mportaut industrial crops dor instance, TO-
baccOl.
p,uw,y SIGNALS AND BLOCKs.-The Highland
Railway of scotland has introduced upon its road
sbat the English journals describe as novel and
ngenious combined block and signal system, the
invention of DR.. Whyte who has devoted several
Gears 10 the work of improving the mechanical ar
rangements for operating railway trans lhe syS-
tenn is entirely sef-acting, and its operations are
performed with the agency Of an electromagnetic
machine of simple construction. An engine run
0ing past say two stations blocks the line ut the
first by raising a scmaphore; places an automatic
sheck against the passing of second engine by the
rinrinp of an alarm bell on the second engine itself,
ehould il attempt to follow announces Its approach
10 the second station or can be stopped by the sta
It clears the line at the previous of both sema-
phore and alarm bell, to leave il free for any
approaching train. The apparatus Itself may be di-
yided into two parts, one being on the engine and
the other connected with the line. -Four wire
brushes each pair metalcally connected are suS-
pended from the engine one pair having battery
and bell in circuit, and the other bell wheel
descends alongside these brushes. On the line, be-
tween the rails, at such distances as may be thought
requisite, or in close proximity TO each station,
series of insulated metallic plates, in an alright
box are laid down. each plate being from five to ten
feet long. By the side of each pair of plates, the
ends of which are connected by wires, Is
placed an electro-magnet. with wires from
battery attached The keeper of the magnet Is
fixed to lever by means of pully, and the ENGINE
travels past, this lever Is pressed upon BY the wheel
above mentioned and the keeper Is forced npagalhSt
tie poles of the magnet. Thus the Scmaphore arm
is raised and the line cfeCtUally blocked. WITH the
view, however TO guard against a possible inatten-
ton the part of the driver of an engine approach
ing the apparatus, the box Is left III such position
that should his engine pass over II while the signal
is up the alarm bell on the engine itself is instantly
rung. The IIst engine having successfully blOckcd
the line in the rear, proceeds to the next station or
signal-pOSt where the line il again blocked ana ny
means OF wires to the last box and mechansm Slln-
lar TO that above described, the olectlo-ma2net ut
the former station is released, the scm2PhOTo
lowered and the way left clear between these two
sections. Thus il is clear that each tram protects
its rear for the distance between each par OF plates.
The line being as il were, divided into sections,
each train as IL enters section instantly D.ocho IL
so that 10 other tram follow until the first has
proceeded without the bell being rlug as warming.
Connected with this automatic clcctncal block sys-
TEN is an arrangement by which each tram can an
nOunce it's approach TO any station, ana another Tor
giving the statOn-mastcr the power 10 stop tram
by causing the bell OH the engine 10 rng. Inc
brushes on the engine are the means by winch this
is accomplished: powerful battery placed nj one
station or smaller batteries placed III suitable po-
apparatus Is operated. As these batteries are never
in circuit except when train works them the waste
is reduced to minimum. The advantages claimed
for this system that being sclf-actlng II entirely
diSpenScs with manual labor, which at some critical
moment is apt to be al fault that ITS certainty of
instantaneous action is secured by the concealment
Of its working parts and their protection from wet
and dust, and finally that the expense OF application
Is comparatively small.
CABRE's CAEAFE ICE MACHINE.-M. Carre, whose
name is well known in connection with the inycn-
ton of several forms of ice-machnes, has lately
added to his achievements in this field by designing
another cOntrivance for the same purpose, which,
for effectiveness, simplicity, and general utility, If
accounts may be credited bids fair to surpass every
thing of this kind that has yet been produced. The
new machine can be easily operated by even an in-
experienced person after one or two trials, and may
be properly designated as family ice-macmne."
The essential parts of the apparatus consist of an
ar-pump, capable of producing a good vacuum.
horizontal cylindrical receiver, partially filled with
sulphuTiC acid, and the caTafe flask in which the