442 
of Linseed steeped and -1 bushel of meal daily | 
along with out straw. Sir E. KERRISON та. 
e hope that the restrictions pin still in some 
districts hinder the growth o таа - 
absorbent roots in 
portion to the sien of its evaporating Es 
in ho s 2 
Professor WirsoN recommended the trial of а 
olose“ cutting reaping мі ine оп а properly M 
rface as like dy result i in a better quality of th 
| те egar rd to wear and tear caused 1 by the direct actio 
| unmasked by the effects of the fire, as the barrel a 
of a locomotive cannot be said to be under the direct 
| er heat. Регһа the vibration of the boiler 
| through the motion on the line may intensify esy — but 
| it is clear that vibration c. be a prim: .The 
majority of the reports are illustrated by саса) пасад 
Eighteen of the 40 ilers gave way at the firebox—11 fro 
the crow insi being blown down upon the 
tube plates; seven from the 
Twenty €— а the barrel ; sait two m 
cellaneous causes, from an originally defective ep and from 
running off t yr Leaving outfall пса whi e curred c 
the fire-box, as the majorit, Miei d t 
у of thes igh 
other infinonoos than direct pressure, FE tho 20 peser ot 
either to inte rnal furrows 0: 
сга ац nd t 
c" at the edge of the inside ov 
the pd pee b pe t| of Уч саш by th: 
joints wi Kv be m ted by the pressure of che 
(See Fig. 
shows distinct traces of lamination 
and i it is probable” that mms o a 
while inferi tal 
Channels er exactly the 
e boilers wit Hh. Jap jotuts Which 
ermany, 
2. е Mechanical Effects of the Heat,.— certain 
e been observed i in 
Jis ex € oded in 
ulled lant » one eat ipt in the way м 
п : m the с d He believed 
at if The 
and of c 
nditare, at vB lima, 
ociety are due to Mr. 
Browne for his address, and for the excellent 
discussion which it has elicited, 
Ox Wednesday of last week Mr. F. A. PAGET, 
C.E. (18, Adam Btreet, , Adelphi, W. C. ), who has 
of Engi neering as agr riculturists are interested 
in, read a ver — paper qom - Society 
and te f Steam Boilers, 
hile 
that boiler inter can assume гү high temperat rhe pe up 
to red heat, authorities differ as to the diminution of ultimate 
is 
e, for they were 
E 2 
rary «ad тонаб а elon 
the Med nig ашсын 
ios observed no effect on the strength of plate 
i abu me 400 F. At a ''scarcely red" heat the 
а king weight of plates was reduced to 16.978 oon uu m 21 
tons at 60° F. ; while at a “ dull red" it was only 1 tons. 
MM. TrémérY and P. Бахт BRIC CE, aided by the celebrated 
Ж at nominally the same tem 
inge during a dull 
Ii iet AX. great vea 
which 18 now o th n om с чэн of gre at | for high Force € ТвЁмЁ Y pec is PRIMIS 
ore conforma ai erience. г. IRBAIRN 
agricultural i importa dată would show that the ultimate strength of wrought iron 
We select such pesas from this paper as Lis is imd to about one-half; but M. TRÉMÉRY's result explains 
the substance of the author's views on өңе the generally instantaneous сы of flues when red hot, and 
a str riotly agricultural subject ; and we де Toen PATA a e been of course originally calculated to a factor of 
thank him for the loan of iid. poi A number of experiments by Lieut.-Colonel H. CLERK, of 
osea: TRE ҮА а ү Mom деп кон а plates, Im distinct 
& dila volum wrought iron, when 
1. On the Effects of Steam Pressure.—In calculating the work- Манту Тр! аы d виду гете а m experiment. 7, for 
ing mere of a cylindrical boiler, the plates are assumed to | instance, “two flat p f wrought i each 12 inches 
be инт а вїеайу баа, and to be submitted toa оше! strain. | long, 6 inches deep, Arg half. an inch thick, were heated and 
The fo of these assumptions is seldom, an and the second is led twenty times, one being imm rsed to ha lf, and tbe 
never ph ere are two principal causes hat te nd to | other to two-thirds, its depth in dur. ior immersed eR 
exert impulsive strains on the sides of the boiler:—1. Тһе | half со: ted or bec. dented on tke A .9 in 
dden euin of the current of steam on its w V da the| the other had similar tions, but ay., б he 
Il - 5 са 2, pe frin — — c" 2 amount. They both turned up into tho form of ki Ek” Eh 
and both m. convex side of which appeared in the portion heated an: d 
MR ddiad; Unfortunately, the в c ред of — Mq 
From 1850 to 1864, 40 locomotive explosions causing a loss of | portions were not tried by Colonel CLERK. А s of 
Fs. 1. of the kind produced cracksin the metal, vies ing 
(Full si the furrowed знана: joint in 
the fre-box nng P a {ела which exploded at Overton 
Station, E: 30th May, 1864. It does not differ from other 
human life have occurred in the United Kingdom. The Boa: 
poene reports in the pH presented to Pull 
ihe ore especially th. Тугкв, R.E., probably 
on bolt CES valusble and series рл теоо extant 
explosions. more especially the case with 
cold feed-water let in near the fire; and, the thicker the plai 
the - dilatation of volume and consequent 
dange Y found that *'iron highly hea and 
ЖОЛЫМ cooled in water, is hardened," being injured, in 
if not afterwards hammered or а: с ermanent 
er 
tion of volume must be necessarily mpanied with a 
р, iui. specific gravity, thus айо ір another Цон т 
о ‚ыз by der - ewe of the mechanical 
Bec that the speci us 
excess of the limit К е ег and His result has been com- 
ES nfirmed b; merous experiments. 
h calls iron Y, е ^ wh mi eer been rendered brittle 
through the often repeated applications of heat, or 
үл 
panied with a dilatation of volume and attendant hardness 
and brittleness, and both seem to be referable to very similar 
мае 
а рут 
the impact of the h: bk he еа T the pw it is 
certain that long-conti zs heat leads to the loss of its 
of iron. —and ially of 
the free oxygen contained in every fla: for a high 
velocity by the draugh he more or less heated plates, 
would also these ch binati upon the sam 
principle as iron filings, thrown through a , burn in 
the air; and upon the same cal principle as the incan- 
escent lime is worn away by the flame of the oxyhy 
en 
a of 
is afforded by the fact that a piece of red-hot iron 
т вазі]. nid eans of a stick of 
снна forming sulphide of iron. 
nce s a the thicker the plate the 
chemical facts also point 
thickness. I 
stro: 
ness. In Germ and po of tl 
still ri. the platte over t| the үе of, for 
pd perpe than anywhere 
chemical an Е ус of the heated fu: 
wear pe бе MA A о, усе AR y At iet 
fire-box pl 
pipes ng il a only i py a^ Sh 
and, with stays four 
nearly 15018. atean [эзген apart, sivo si^ a aed 
THE GARDENERS CHRONICLE AND AGRICULTURAL GAZETTE. 
of в 
E ou геу de | имел 
On the Effects of the Feed- -water. 
bra i - acid or alka 
e for years 
show a numb 
human гасен „Or Pies the maj ar 
e moon's surface, (Bos The 
лај crater e 
Or has ais 
Xp internal surface of а iron boiler 
showing, чен quarter of s fal size, e M н 
ссе of piti = ) Н » “ppan 
sometimes о bi ved ma: x ко lit in A 
like this ed : geh rwise show 
intact. etim € uv vias i ТОНЕ d pitted Ee 
bolt ; pium e plat: wl be perfectly кес Е 
тоа toit wit be mtl eaten away, both been the 
same time at work, and under, of 
ЕЕ Liner smt 
ave run the same distance 
Besides, € E boilers, with or pes 
r used for stat nary, locomotive, or marine 
noat all the circumstances 
e following :—Mr. T, in a report addressed 
" tho British. Амач Some erti аёо; КОКЕ that wrought 
iron and steel ew аа probably), “* consist of two or mors 
— сосен pounds, coherent and interlaced, of 
ele ө e other. i 
explains how above the 
in marine БОНА, get very {ЙУ соттой 
another part of perh ө the same plate is scarcely affected. 
The T MN in a marine boiler is known iol 
genera 
ucial test of this explanation of pitting would be tte 
бена of the Asi. of ies dace from plates d 
ап} electro-homogeneous charac This homogeneity coul 
late cnt from. 
hotograph of surface of corroded p ; Le 
d the S T med peer on Wednesday о с? 
17th, 1864, at Abera: orks, fon jato тава 
sion was inter al, eg 3 's0m6 parts P 
than one-eighth thick.  Thirtee n persons 
many others ly in, 
vene of tempera 
NUI 
—————— 
