1831.] 
Notice of Coal near Hoshungabad. 
293 
construction and preservation of rods, from the influence of the weather. When 
this has been done, there appears to me, from the numerous facts on record, no 
truth better established in Natural Philosophy, than that of rods, when properly 
constructed, preventing the fatal effects of lightning. 
The following remarks on the best kind of conducting rods may not be consi- 
dered useless. 
1st. A bar of iron, 2 inches in diameter, gradually diminishing in size to its 
upper extremity, and sufficiently long to extend 4 or 5 feet above the highest part 
of the building, and terminating in an inch of pointed platina, or a foot and a half 
of gilt copper, which retains its fine points. The thick end of the rod is to 
terminate in a thinner piece of 10 or 12 feet long, which after passing through a 
cylindrical cavity of brick-work filled with charcoal, is to extend from 
the building in the direction of a well or river, and terminate in several 
points. To defend this termination of the rod from rust, and to convey the 
electricity more readily to the ground, the charcoal will be found useful. The con- 
ductor is to be fixed to the building by a thick block of wood, so as to raise it 
about two feet from the surface. 
2dly. The extent to which these rods defend buildings is said to form a circle 
with a radius the length of the conductor. So that a building of 140 feet in diame- 
ter may be defended by a rod of 70 feet*. When two conductors are required 
on the same house, the upper part may be made to branch off along the building, 
having several points on the top raised from it. 
3dly. The part of the house which is highest and nearest to any body of water 
18 1() he preferred for the erection of conducting rods. 
the erection of such rods will not cost more than from 20 to 30 rupees: as they 
f orm a certain prevention against the dangerous, and destructive effects of lightning, 
lt ,na y he naturally asked — why then should any one endanger his life and proper* 
when it can be avoided on such easy terms ? 
J une, 1831. 
IX . — Notice of Coal near Hoshungabad. By J. Finnis, Esq. 
[Read at a Meeting of the Physical Class.] 
The Coal strata are observable on both banks of the Bhoora Nuddea, near a 
high hill called Jamgurh, about 33 miles south of Hoshungabad, and 8 miles 
Sout h ot Bhoorda, the head of a Pergunnah in the Baitool district, on the west 
01 the road going to Baitool. The river apparently has cut its way through the 
JC( > thence runs eastward, and empties itself into the Towah ; in which river the 
°°al was first discovered, and which gave rise to the supposition, that the coal was 
*° h e found somewhere on the banks of the former river. I make no hesitation in 
l - ln g> that the discovery will not prove of any benefit to trade, owing to thepoor- 
Dess °f ^ le coal, its scarcity, its out of the way situation, and the difficulty of work- 
ti ll * ^ le rou £h sketch I have the pleasure to send, (PI. XIV. figs. 1 and 2) with 
e specimens, will aid you in comprehending my descriptive account of the posi- 
11 l ^e several minerals. The bed extends N. and S. dips to the W. and does 
fo*ppear E. of the ghaut. Length from the ghaut to where it disappears 16 feet, 
as ° ^ eart h on which the coal bed lies; its depth could not be well 
ained, owing to the water of the river coming in : it is however above one foot. 
^ very thin stratum, two inches thick, of coal ; does not extend far west, 
a Ppears to pass into No. 3 bituminous shale, a stratum four inches in thick- 
* Annales de Chimie, xxvi. 1824. 
