April i, 1882.] 
THE TROPICAL AGRICULTURIST. 
first at G o'clock and during the- short days at 5 o'clock, 
every evening except Sunday, continuing their action 
until dawn. The outside light was protected l. v a clear 
glass lantern, while the light inside the house was left 
naked in the earlier experiments, one of my ohjocts 
being to ascertain the relative effect of the light under 
those two conditions. The inside light was placed at 
ono side over the entranco into the houso, in front of 
metallic reflector to save the rays that would otherwise 
be lost to the plants inside the houso. Tho houso was 
planted in tho first placo with peas, French beans, 
wheat, barley, aud oats, as woll as with cauliflowers, 
strawberries, raspberries, poaches, tomatoes, vines, and 
a variety of flowering plants, including roses, rhodo- 
dendrons, and azaleas. All these plants being of a 
comparatively hardy character, tho temperature in (his 
houso was maintained as nearly as possible at 60 deg. 
Fahr. Tho early effects observed were anything but 
satisfactory. While under the influence of the light 
suspended in tho open air over tho sunk houses the 
boueticial effect due to the electric light observed during 
tho previous winter repeated themselves, but the plants 
in tho houso with the naked electric light soon mani- 
fested a withered appearance. Was this result the effect 
of tho naked light, or was it tho effect of the chemi- 
cal products — nitrogenous compounds and carbonic acid — 
which are produced in tho electric arc ? Proceeding on 
tho first-named assumption, and with a view of soften- 
ing the ray of the electric arc, small jets of steam 
were introduced into tho house through tubes drawing 
in atmospheric air with the steam, and producing the 
effects of clouds interposing themselves in an irregular 
fashion between tho light and the plants. This treat- 
ment was decidedly beneficial to the plants. Having in 
consequence of preliminary inquiries determined to sur- 
round tho electric arc with a clear glass lantern, more 
satisfactory results were soon observable. Thus peas 
which had been sown at the . end of October produced 
a harvest of ripe fruit on the lGtli of February, under 
the influence, with tho ex 
continuous light. Haspberi 
on the 16th of Decembej 
1st of March, and strawb* 
same time produced ripe fruit of excellent flavour and 
colour on tho 14th of February. Vines which broke on 
tho 26th of December produced ripe grapes of stronger 
flavour than usual on tho 10th of March. Wheat, 
barley, and oats shot up with extraordinary rapidity 
under tho influence of continuous light, but did not 
arrive at maturity ; their growth having been too rapid 
for their strength caused them to fall to the ground 
after having attained tho height of about 12 inches. 
Seeds of wheat, barley, and oats planted in the open 
air and grown under the influence of the external electric 
light produced, however, more satisfactory results ; 
having been sown in rows on the Gth of January, they 
germinated with dillieulty on account of frost and snow 
on the ground, but developed rapidly when milder 
weather sot in, and showed ripe grain by tho end of 
June, having been aided in their growth by the electric 
light until the beginning of May. Doubts have been 
expressed by some botanists whether plants grown and 
brought to maturity under the influence of continuous 
light would produce fruit capable of reproduction; and 
in order to test this question, tho peas gathered on 
the 16th of February from the plants which had been 
grown under almost continuous light action were 
on the 18th of February. They vegetated in a few 
days, showing every appearance of healthy growth. 
Further evidence on the same question w ill be obtained 
by Dr. Gilbert, F.H.S., who lias undertaken to experi- 
ment upon the wheat, barley, and oats grown as above 
stated, but still more evidence will probably be roqnired 
before all doubt on the subject can bo allayed. 1 am 
aware that the great weight of the opinion of Mr. 
Darwin goes in favour of the riefl that many plants. 
cs put into tho house 
ced ripe fruit on the 
mts put in about the 
alten 
any : 
perim 
annuals, do reqiurc. The 
electric light has been ve] 
palm, which at two periods 
its early growth and at the 
ment, was placed (in Febru 
1881) under the night ac 
lights, set behind glass at i 
yards from the plant. The 
weighing 75 lb., each bana 
pronounced by competent : 
flavour. Melons also remar 
flavour have been produced 
tinuous light in the early s 
I am confident that still b 
when the best conditions o 
mity to the electric light h 
sated. Mv obiect hitherto 1 
horti 
and 
ducii 
distant when t 
adjunct to tli 
■xtivi 
was a bunch of fruit 
ig of usual size, and 
to bo unsurpassed in 
or size and aromatic 
the influence of con- 
>f 1880 and 1881, and 
jsults may be realized 
nature and of proxi- 
n thoroughly investi- 
3 think that the time 
c light will be found 
at the disposal of the 
independent of climate 
ith a power of pro- 
ro-horticulture can be 
the 
meraie cost, comprising 
and wear and tear of, and interest 
.ml machinery employed, which ex- 
has already shown to amount to 3d. 
i of 5,000 caudles. The personal cur- 
isito in that case consists simply in 
n electrodes every six or eight hours, 
without appreciable expense by the 
hargo of the fires of the greenhouses, 
tural source of power was available, 
3 had to be resorted to. The engine, 
rse-power, which I employ to work 
lights of 5,000 candle-power, each 
coal per hour (the engine being of 
pressure type), which, taken at 20s. 
to (id. or to 3d. per light of 
5,000 candles. But against this expenditure has to bo 
placed tho saving of fuel effected in suppressing tho 
stoves for heating the greenhouses, the amount of which 
I have not been able to ascertain accurately, but it 
may safely be taken at two-thuds of the cost of coal 
for the engine, thus reducing the cost of the fuel per 
light to Id. per hour; the total cost per light of 5,0(10 
candles will thus amount to Gd. p/tu Id., equal to 7il. 
per hour. This calculation would hold good if the 
electric light ami engine-power were required during, 
say, 12 hours per diem, inasmuch as tin iigbt is not 
required during the daytime, aud tho tiring of the boiler 
has nevertheless to bo kept up in order to supply beat 
to the greenhouses, it appears that dining the daytimo 
