ward, and in the axis of the instrument the sound
was about as effective as that of the 8-oz. rocket. But in a
direction at right angles to the axis, and still more in the rear of
this direction, the syren fell very sensibly behind even the 2-oz.
rocket.

These are the principal comparative trials made between the gun-cotton
rocket and other fog-signals; but they are not the only ones. On the
2nd of August, 1877, for example, experiments were made at Lundy
Island with the following results. At 2 miles distant from the
firing-point, with land intervening, the 18-pounder, firing a 3-lb.
charge, was quite unheard. Both the 4-oz. rocket and the 8-oz.
rocket, however, reached an elevation which commanded the acoustic
shadow, and yielded loud reports. When both were in view the rockets
were still superior to the gun. On the 6th of August, at St. Ann's,
the 4-oz. and 8-oz. rockets proved superior to the syren. On the
Shambles Light-vessel, when a pressure of 13 lbs. was employed to
sound the syren, the rockets proved greatly superior to that
instrument. Proceeding along the sea margin at Flamboro' Head, Mr.
Edwards states that at a distance of 1.25 mile, with the 18-pounder
previously used as a fog-signal hidden behind the cliffs, its report
was quite unheard, while the 4-oz. rocket, rising to an elevation
which brought it clearly into view, yielded a powerful sound in the
face of an opposing wind.

On the evening of February 9th, 1877, a remarkable series of
experiments were made by Mr. Prentice at Stowmarket with the
gun-cotton rocket. From the report with which he has kindly furnished
me I extract the following particulars. The first column in the
annexed statement contains the name of the place of observation, the
second its distance from the firing-point, and the third the result
observed:

Stoke Hill, Ipswich 10 miles Rockets clearly seen and sounds
distinctly heard 53 seconds after the flash.

Melton 15 miles Signals distinctly heard. Thought at
first that sounds were reverberated
from the sea.

Framlingham 18 miles Signals very distinctly heard, both in
the open air and in a closed room.
Wind in favour of sound.

Stratford. 19 miles St. Andrews Reports loud; startled
pheasants in a cover close by.

Tuddenham.