THE TROPICAL AGRICULTURIST. [September i, 1888. 
Permanent posts 889 ; eay 890 to the acre 360 
Letting down. 340 
Transport of posts (this depends on 
distance 400 
2nd application of burnt earth 1 Picul. 
Burning and applying 170 
Supplying and nursery 57 
Upkeep roads and drains 54 
One man tying 1500 vines for 6 months $ 54 
One man tying 500 vines for 6 
months $162 216 
Weeding at 45c. per acre 54 
Contingencies, purchase of ladders, etc. 100 
Total expenditure pepper 18 months old 3074 
Tying, one man, 500 vines 324 
3rd application of burnt earth, burning 
and applying 340 
Nursery 54 
Supplying, shading 15 
Weeding at 50c. per acre 60 
Building a small store 300 
Purchase of small dryer, fanner 120 
Curing and transport of 45 ~) ^ 
Piculs Pepper ) 
Contingencies, Tools, Sacking 150 
Total for Pepper 2* years old 
„ „ (one year) 3J „ 
j> i) ( » » ) ^4 )> 
4,482 
1,000 
1,200 
Total §6,682 
Crop :— 
Sale of 50,000 rooted cuttings ) 
In 2 years, $15 per 1000 J 
Sale of 45 Piculs Pepper off 1 
2J year old vines f 
Sale of 134 Piculs Pepper off) 
3iyear old vines at 14 catt. J 
Sale of 267 Piculs Pepper off ) 
4J year old vines at 3 catt. } 
Profit off 10 acres Pepper 4£ 1 
years old ) 
I have put down $ 15 per picul as value of Pep- 
per. I have further made no allowance or salary, 
bungalows, lines, etc., nor for purchase of land and 
interest, as I fancy, beyond my own district, the 
estimate of expenditure may not be of any great 
use, owing to cost of labour. 
Planter. 
750 
675 
2,010 
4,005 
$758 
PROTECTION FROM LIGHTING. 
Professor Oliver Lodge has, during the past 
spring, been delivering before the Society of Arts 
a series of lectures on the protection of buildings 
from lightning. The visitations of lightniDg in this 
country are sufficiently frequent and sufficiently 
serious to constitute the subject one of special 
interest. In the course of these lectures, the learned 
Professor has not only suggested numerous improve- 
ments in the existing methods of protection, but 
has, at the same time, given his audience much 
interesting information about lightning itself and 
the peculiarities of its behaviour. One hundred 
and fifty years ago practically nothing was known 
about the subject, and it was not until 1751, when 
Benjamin Franklin flew his kite at Philadelphia, 
that proof was obtained that lightning was, in fact, 
nothing more than a huge electric spark. No 
•sooner was the nature of lightning thus explained, 
than the slight electrical knowledge which people 
then possessed was utilised to protect buildings 
and ships from its destructive agency, though, from 
a want of clear perception of its action the pro- 
tection as then applied was sometimes quite illusory, 
at others positively harmful. Atmospheric electricity 
is presumably factional, occasioned by the friction 
of mist against dust and ice particles, in the air. 
Hence thunderstorms are most frequent when, 
after a spell of dry weather has filled the air 
with dust, a damp mist-bearing current mixes 
with a current of dry air ; as for example when 
the south-west monsoon penetrates into the dry, 
dust laden atmosphere of Upper India. Electricity 
is apparently first generated in the upper atmos- 
phere, and so long as there are no clouds it is 
possible for a very high state of electrification to 
exist in these regions without any ill-effects 
following ; but clouds act ai conductors, and by 
their means the electricity is brought down into 
the lower atmospheric strata, until at last it comes 
to within sparking distance of the earth. When 
this condition has been established the portion 
of the earth's surface covered by the cloud, the 
intervening stratum of air, and the cloud itself, 
together form a 6ort of natural Leyden jar, the 
cloud forming one coating of the jar, the earth 
the other, and the air acting as the glass or 
dielectric between them. Now it can be shown 
by laboratory experiments that if electricity is 
poured into a Leyden jar, there arrives a time 
when the tension becomes so great that a discharge 
between the two metal coatings takes place, the 
glass is pierced and the tension is relieved. An 
exactly similar action occurs in nature. By pro- 
cess which need not be explained here, the electri- 
fication of the natural Leyden jar at certain times 
increases with alarming rapidity, the coatings draw 
together some portion of the cloud covering 
descending towards the earth, till they reach 
sparking distance, and then with a crash the 
discharge takes place. The dielectrio (the air) is 
pierced just as the case with the glass in the 
Leyden jar, and any opposing obstacles such as 
men, animals or buildings are not uncommonly 
destroyed. 
For a very considerable period after the discovery 
of the nature of lightning the erection 
of lightning rods was strongly opposed by all 
the religious fraternities. The old idea that 
the lightning was Heaven's destroying fire clung to 
them, and it was considered impious to interfere 
or try to prevent the destruction which, for some 
wise purpose, was no doubt providentially designed. 
After a time, however, the heretical rods became 
fairly common, first in Protestant Germany and 
subsequently in France and England, and now 
the only difficulty that Professor Lodge encounters 
in his advocacy of lightning rods is to induce 
people to abandon their old ideas and adopt the 
precautions which recent advances in science have 
shown to be necessary for proper protection. 
Numbers of people still believe that a lightning- 
rod proteots a circular area, of which the height of 
its point from the ground is the radius ; others, 
that a ball at the top of the conductor is the correct 
arrangement ; whilst not a few insist that if the 
"earth" end of the conductor be connected to a 
small water-butt, or pool, all the proper precau- 
tions have been taken. Each of these ideas is 
distinctly erroneous. As regards the first, Pro- 
fessor Lodge says all such ideas as areas of pro- 
tection are perfectly illusory, and of the second, that 
points to the sky are now recognised as unques- 
tionably correct. To those who firmly believed 
that once the "earth" end of a conductor 
is led to water all danger is over, the Professor 
replies that, as a matter of fact, there is no safety 
in water unless it form a large, continuous sheet, and 
most certainly any large flash whioh was discharged 
into a water-butt or small pool of water would make 
a very considerable disturbance when it left the 
conductor. * * * 
The conclusions from these experiments are that, 
