91—1848. } THE GARDENERS’ CHRONICLE. 333 
—— to j ly on ‘the outside. The ese cups are su ported by contact will cool ion, and will be- 
ian wand it is recommended to cut them off as they | by fine * tubes, provided with covers of the same . — covered with dew, vie he varnish beneath the 
appear the of fi fruit, and] nature, and the ere exposed to the air on a calm | small 5 can only cool by contact. And we find that 
— the parent —— — — has the fine night. One of thermometer was black- the ce of the . circle remains per- 
of so it | ened, and the other two were in the tate, and | fect} y dys metallic band is wetted to 
roval that 
nit We safe to follow it ourselves, s — i it, should be 
e questioned 
nee 0 
row and carefully cut off fall a rs; let six more, 
be left to nature. Then the state of 
opera upo a $ 
res 2 I am incline 
ney Ma rom ‘the — — of — ms — 
— hemp i :—As as 
another follows, and this continues through — — 
of growth. * . ne rem runner was a 
final process, uced, oe L* 
bearing of the — — bays fruit anà the plant 
not be doubtful 5 as when Pea ches re removed 1 — 
a tree, I their places, the 
juices which drr have matured pre o to those 
But if a fresh Peach w 0 
place of the one helen off, would any one practise the 
system of 8 ? Here again di i i 
wan an be carried on in the follo ay 
w ow on one wer * ap Esi 
a month hence ; and 
be kept of 2 weight of all moe removed from another 
similar plant during the e peri he balance 
struck between = two — will tell more truth 
theory can 
As anew bed of Strawberries should be made Kasaad 
year so that a fresh healthy stock may be alwa, 
as many runners 
unless rd of caution in reference to gat 
ing the qesd The N ae — ce this Himself 
r trus an experien he 
—— to — the fall. benefit of f his — It is really 
atrocious to pink away at a truss of fruit as eager 
visitors will sometimes do; gaining one and often 
destro meyin ga — * - by oe same 2 
attack, This may im old- 
fashioned S aaa —— — beds —— little at- 
tention ; but when they 8 pomi arii it is 
vexatious to ——— a erop . e corn a field 
having a footpath through it.— H. B 
— THEORY OF DEW 
of M. Melloni * a philoso eopher and the 
taches to the subject of dew, has —— us to 
abridg * ee the“ ate Rendus” the three letters of which 
the following is the 
vi ST LE 
ete — 
hat attac 
, From the experiments undertaken by Wells to "i ie 
can e or entirely prevent the deposition of dew on | hand fork 
and prove conclusively 3 it . 
of co 
8 seems quite clear, I 
* — the ear th nor falls 
wood, g 
dew. a banesa they emit heat easily, anda 
cooled under a clear sky. Metals, o e other hand, 
erence is obs 
rect; but it must be allowed 
him, attributed the absen nce of me on 
to 
an electric fi force; L is 
the 
. — radiation of silver with that of lampblack. 
first shut, the 
uld sain S, viz., 
t| lamina 
it does ~a eee 
bekas o to everybody. Indeed, Prevos aussure | 
apparatus with which I compared t 
cups to be p Parapar or ome- 
rk sam tempera Then by 
aomas two of the — — leaving hs third, contain- 
ing one of the bright thermometers, shut, it v rill be 
seen that the metallic thermometer whic now 
exposed to the air, falls so little ny hardly any change | 
be observe cept wit nest instrumen 
N 
exposed thermom iyre sults 
manner, the arinn vate a 
that the em e 
less than the “experiments of Leslie, Dulong, and Petit 
led people to 
The Naias power of lampblack being 100, that of 
ilver I found to be 3:026. MM. La 
nt eman 
ted silver burni 
rom obse a made in 1838, I am led to believe 
that the differences in the radiating bn of the 
polished and the scratched side — the e om anne 5 
; 
which remains quite and b 
ed | small circular 
n 
f metals is much | part 
its very zig, if the — i is e damp. 
he 
another h we could 
not so easily — — aT — — exact repeti- 
on of the same appearances on the surlace of the dise 
turned next the gro n ins to a this 
appear 
surface exactly opposite the little exterior 3 
band ; a light white circle et 8 appears on the 
polis metal, comming 3 . 
spreads little b 
the plate in one direction, but never * hes 
brilliant, like the corre- 
sponding pe p the other side of the ap an 
which covers it withou 
ec 
ne not 1 aqueous vapour whi ich forms dew, n nor do 
since — see some parts of the metal quite wet, and 
others q 
The 
e of the dew first on the uncovered 
3 
—.— 
gradual extension to the other 
band of — and its its 
adjacent and oppos 
eases of the thermometers exposed free] 
prove ure consequence 
radiation, which gives to good radiators the degree of 
cold necess: aa for the condensation of the elastic invi- 
xperiment, is not ow erally 
to the differences in the mechanical — of 
Apre | 
— a be compressed 
se will be less after the 
scratching than it was before, is sam 
of silver, melted and polished, per its radiating power 
diminished by being hammered minate 
varnish, black- 
lead, isinglass, sawdust, „earth, a 
A a very en fa fall of temperatu e be: 
wit . 
ot ue at ‘all daring 1 9 
ecurred the more yes erg the higher the 
w ced a 
ar to those described 
fin 
ur which pervades our atm 
thus far all the facts agree perfectly with the gene- 
— n in the usual way, but 
nected in a fortunate manner to the prineiple of Wells, 
eee, 
a 
follows and never precedes the produ oO 
shed . 
d mp 
p e ‘provided there was no trace of fog in the atmo- 
here 
Hence we see that in order that a body ar Mang 
ere by dew it must first e ool to a certain d 
metals 65 not become erit 4 with 
by 
hen take 
— surfaces and watery va 
that = fi the h, 
plained met hg e thin e heat - electricity 
aa gaged by th a on dy fibres of m th 
particles of this same vapour, at the 3 of their 
e to the liquid state. To show that these 
ee 
pour; and those 
a commo imble, 
contain che bulb of the 9 
uated tube. 
the ls wo oh eae 
bys ‘Particular ‘repulsion, which, he said, existed be- 
metallic | 
eja hele in the centre of t 
The t dise is 
rs | other, at ae 
e positi 
the night is and 
in, sr a will soon 1 observed 
o metallic pieces (which 
places 
si e grea B be pushed along the wire 
until the two dises are t 5 millimetres 
istance they must be kept. 
horizontal 
ith any other bodies. If 
the larg 
ia on a indeed to rem 
which the nstrument was left, . ee 
ee * hence nular 
part of the lower disc 
Ein der thet this band wil radiate heat, cool, become 
covered w cold and dew in con- 
reason—the points cooled 
] e dises ned are to be taken in the evening out | i 
in the fields, pir left aa: a few minutesin a 
came roduced a similar detection. This plant 
the oa ‘at which point en between the 
se g ‘and escending m. io =a were 
ne — of a like — oceurre n the 
ma 
TY instant, an a larva of similar size (I think z in its 
third year), was e 3 red neighbour has 
dew is that they do not become sufficiently cold by | thus lost two plants within the week, but has failed to 
radiation, But is there nothing else to hinder the pre- trace the marauder, Th e hints may be 
cipitation of dew on metals? I er words, is the | acceptable and useful.—J. T y 16. 
feeble radiating power of metals the tru 0 ines.—I lately stated many of my Vine-buds 
reason why they are never wetted by dew the appearance of being bitten, and that I should 
The following ex ent seems to me to answer this be obliged by a remedy. Since I wrote I applied wet- 
question, at th e time that it refutes the theories lime putty to the injured places. A day or two aſter- 
that dew rises from the falls from the clouds, | wards I observ my the Pidi were swelling instead of 
and clearly proves kerin principle :—On a ti e, as falling away, an w eve which was not too far 
large an as e, draw a concentric circle with | gone is in leaf 220 quite healthy. The lime putty did 
tog Ary and | not i inj e buds or leaves. I 
es w ere 
sive 3 eee are now in vigorous 
3 shod to “A. fe the I — to say ht Tey 
wa 
h | Lloyd, O 
ai eb 
growing upon it for have now tak 
it a —C. A. A, 
Pea.—This is but name for the old 
Grotto Pea, first introduced by Messrs. Field and Child, 
