Advantage of elevated pointed Conductors. 837 
Fom the tenth and eleventh experiments we learn, 
that the metallic part of our conductor being feparated 
or difcontinued is the reafon that our artificial cloud does 
ftrike to the point; and that it ftrikes further to the point 
as the number of the reparations are increafed; and that 
if the metallic communication with the moift earth be 
made compleat, that then our charged cloud will not 
ftrike to the point. 
When a conductor to a building, terminating in a 
point, has been ftruck, l am inclined to think, that there 
had not been a compleat and fufficient metallic commu- 
nication with moift earth; and from all the accounts I 
have met with, this feems to have been the caufe of their 
having been ftruck. From the twelfth experiment we 
learn, that a very fine wire will conduit a ftrong fpark. 
Fig. 3. reprefents a moveable artificial cloud : it con- 
lifts of a hollow tube of wood, with a ball at each end, 
being together about fix feet in length : from each end 
was fufpended a light hollow wooden cylinder ee; thefe 
with the balls and tube were covered with tin-foil : it 
was placed with its axis refting on two femi-circular hol- 
lows in a piece of brafs fixed on a glafs pillar, by which 
it was infulated : it moved very eafily on its axis, and was 
brought to a horizontal pofition by means of two move- 
able pieces ff. 
£ X P E* 
