124} Mr. Snow Harris on Lightning Conductors 
Kow the separate pieces of leaf-gold thus placed, may be taken 
to represent detached conducting masses fortuitously placed 
along the mast and hull of a ship. 
Exp. 2. Let a thin continuous line, be passed through 
the separated pieces, and a dense accumulation discharged 
over the whole, as in the preceding case. The effect will be 
as represented in fig. 6. : the discharge will be confined to the 
line of least resistance; and we may perceive in this, as in the 
former case, that those pieces, or parts of pieces, out of the 
track of the discharge, are not affected ; thus a part only of the 
piece g is destroyed, also of the piece /, whilst other pieces, 
bi Z, which in the former case, where the continuous 
line, h, was not present, were blackened by the discharge, 
remain here perfect. 
Exp. 3. If the continuous line A, B (figs. 7, 8) be assisted 
by other comparatively short collateral branches, fxs d d c, 
having one common connexion at B, then a discharge which 
would destroy the line A, B, will divide upon these auxiliary 
lines, and the part tZ, B will either escape, or the whole will 
suffer together. 
Exp. 4. Pass a discharge over a strip of gold-leaf, as A, 
fig. 2; every part of it, as indicated by the last experiment, will 
participate in the shock ; and if it be of uniform density and 
thickness it will be everywhere equally affected, so that one 
portion will not be destroyed without the whole. This result 
will be readily distinguished from that represented at d and i, 
fig. 5, where the masses lie across the track of the discharge. 
The diagrams here referred to, are copied from the actual 
effects of the electrical discharge in the way above mentioned. 
18. These experiments are instructive. They evidently 
prove, that an electrical explosion will not leave a good con- 
ductor, constituting an efficient line of action, to fall upon 
bodies out of that line. Mr. Sturgeon’s assertion that a con- 
ductor on a ship’s mast would operate on the magazine is 
therefore quite unwarranted. Besides, we have many instances 
of the masts having been shivered by lightning into the step, 
whilst acting as partial conductors, without any such conse- 
quence; as happened in the Mignonne in the West Indies, 
the Thetis at Rio, the London, Gibraltar, Goliath, and many 
others. Instead, therefore, of a conductor on the mast being 
dangerous, it is absolutely requisite as a source of safety to the 
ship, by confining the discharge to a given line and leading it 
to the sea. 
19. It was from a careful consideration of the common ef- 
fects of lightning, and from such experimental facts as those 
above mentioned, that I was led to suggest the propriety of 
