(3/11. "Annales de Chimie et de Physique" tome 37 page 319.) They
failed both with powdered feldspar and quartz. One tube, formed
with pounded glass, was very nearly an inch long, namely .982, and
had an internal diameter of .019 of an inch. When we hear that the
strongest battery in Paris was used, and that its power on a
substance of such easy fusibility as glass was to form tubes so
diminutive, we must feel greatly astonished at the force of a shock
of lightning, which, striking the sand in several places, has
formed cylinders, in one instance of at least thirty feet long, and
having an internal bore, where not compressed, of full an inch and
a half; and this in a material so extraordinarily refractory as
quartz!
The tubes, as I have already remarked, enter the sand nearly in a
vertical direction. One, however, which was less regular than the
others, deviated from a right line, at the most considerable bend,
to the amount of thirty-three degrees. From this same tube, two
small branches, about a foot apart, were sent off; one pointed
downwards, and the other upwards. This latter case is remarkable,
as the electric fluid must have turned back at the acute angle of
26 degrees, to the line of its main course.
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