280 KANSAS CITY REVIEW OF SCIENCE. 
ures four feet long by three feet broad and one foot thick, but of irregular shape. 
On the edge of the craig the lightning detached a mass of rock, which now stands. 
in a very precarious position. This large mass measures four feet nine inches 
long by three feet broad and one foot four inches thick. The top of the craig, a 
short distance from the front of it, is covered with a coating of angular pieces of 
basalt, and on the top of these a covering of sod. It was on the sod the light- 
ning struck, and made a hole two feet six inches long by one foot six inches. 
broad. The largest diameter of the hole is in a direction from N. W. toS. E. 
and the lightning continued its course in this direction, ploughing a furrow in the 
sod for a distance of nineteen yards, the furrow diminishing in width as it receded 
from the original hole, where it measures five inches wide. These facts establish 
the direction in which the lightning came, and correspond with the observations 
of three gentlemen who were in a house on the west side of the Hunter’s Bog, 
and saw the lightning pass across the Bog to the rock on the east side, namely 
from N. W. toS. E. Inthe Z2mes of the 14th of October last, notice was given 
that a committee of scientific gentlemen had been appointed by insurance and. 
other companies to investigate the effects of lightning with a view to providing 
the best means for protecting buildings, and a request was made that all persons 
who could furnish information on this subject would do so. In consequence of 
this notice I wrote a letter to the Zzmes on the 25th of October, containing the 
following information, which it is important persons should know who wish to: 
watch thunder-storms, and give the information asked. There are three kinds of 
thunder-storms. First, those that take place between clouds, the lightning 
flashing from cloud to cloud; second, storms in which the lightning comes from: 
the clouds down to the earth; third,storms in which the lightning passes from the 
earth to the clouds. It is the two latter kinds of thunder-storms which affect the 
question of the protection of buildings. The damage done to them and to trees. 
by lightning varies in a remarkable manner, according to whether the lightning 
went from the earth to the cloud or from the cloud to the earth. 
‘“The lightning which struck the Dasses Craig has an important bearing 
with reference to the protection of buildings from lightning. ‘The common theory 
is that lightning will always be attracted to strike the highest or most prominent 
point in its vicinity. The Dasses Craig is near the bottom of the valley, bounded. 
by Salisbury Craigs on the W. and S., and Arthur’s Seat on the E. High land 
and prominent rocks surrounded this craig on all sides, and yet the lightning 
passed all these and descended into the valley to strike it. 
‘“Another interesting fact. On placing a compass near the hole made by 
the lightning I found that the needle deviated from N. to E., and when the com- 
pass was in the hole, the needle stood at E. S. E., instead of N., proving that 
the rock was still powerfully electrical at the spot where the lightning struck it. 
But, except in the vicinity of the hole, the craig did not affect the needle.”— The 
Telegraphic Journal. 
