430 Dr. Moll’s account of the experiments on 
be possible to fire continually guns at a distance of 9 miles 
exactly at the same second ; but the very great attention and 
ability of our artillery men overcame this difficulty. Be- 
tween our shots at the two stations there was never a greater 
difference than 1 ” or 2", whilst this difference in the experi- 
ments of the French philosophers of 1822, went to 5 minutes. 
This exact correspondance in the firing of the guns was 
obtained in the following manner. At each station an officer 
had the chronometer placed before him on a small fable 
very near the gun ; a non-commissioned officer or gentle- 
man cadet stood ready with the port fire near the touch- 
hole ; and at the instant required the officer holding the 
chronometer pressed the arm of the person who was to fire 
the gun, which went off at the very moment. With a little 
practice they were certain to fire the gun at any given 
second. 
The first night of our experiments, the 23d, 24th, and 25th 
of January, 1823, we experienced fhe same annoyance of 
which the French philosophers had to complain the first night 
of theirs. The report of the shots of Zevenboompjes was not 
heard at all at the station of Kooltjesberg. But at Zeven- 
boompjes all the shots of Kooltjesberg were distinctly heard. 
After the first night We constantly used the metal twelve 
pounders loaded with 6lbs. of gunpowder. The 26th of Janu- 
ary all the shots were heard at Kooltjesberg, but none were 
perceived at the opposite place. But thfe wind shifting the 
following night, a good number of corresponding or simulta- 
neous shots were distinctly heard on both stations. The 
particulars of the experiments made in these different days 
will be found in the tables annexed to this paper. The dis- 
