The cotton-powder yielded a very effective report. The rockets in general had a slight advantage over the same quantities of material fired near the ground. The loudness of the sound was by no means proportional to the quantity of the material exploded, 8 oz. yielding very nearly as loud a report as 1 lb. The 'aerial echoes,' which invariably followed the explosion of the rockets, were loud and long-continued. On the 17th of October, 1877, another series of experiments with howitzers and rockets was carried out at Shoeburyness. The charge of the howitzer was 3 lbs. of L. G. powder. The charges of the rockets were 12 oz, 8 oz, 4 oz, and 2 oz. of gun-cotton respectively. The gun and the four rockets constituted a series, and eight series were fired during the afternoon of the 17th. The observations were made from the 'Vestal' and the 'Galatea,' positions being successively assumed which permitted the sound to reach the observers with the Wind, against the wind, and across the wind. The distance of the 'Galatea' varied from 3 to 7 miles, that of the 'Vestal,' which was more restricted in her movements, being 2 to 3 miles. Briefly summed up, the result is that the howitzer, firing a 3-lb. charge, which it will be remembered was our best gun at 'the South Foreland, was beaten by the 12-oz. rocket, by the 8-oz. rocket, and by the 4-oz. rocket. The 2-oz. rocket alone fell behind the howitzer. It is worth while recording the distances at which some of the sounds were heard on the day now referred to: 1. Leigh 6.5 miles W.N.W. 24 out of 40 sounds heard. 2. Girdler 12 miles S.E. by E. 5 out of 40 sounds heard. Light-vessel 3. Reculvers 171 miles S.E. by S. 18 out of 40 sounds heard. 4. St. Nicholas 20 miles S.E. 3 out of 40 sounds heard. 5. Epple Bay 22 miles S.E. by E. 19 out of 40 sounds heard. 6. Westgate 23 miles S.E. by E. 9 out of 40 sounds heard. 7. Kingsgate 25 miles S.E. by E. 8 out of 40 sounds heard. The day was cloudy, with occasional showers of drizzling rain; the wind about N.W. by N. all day; at times squally, rising to a force of 6 or 7 and sometimes dropping to a force of 2 or 3. The station at Leigh excepted, all these places were to leeward of Shoeburyness. At four other stations to leeward, varying in distance from 15.5 to 24.5 miles, nothing was heard, while at eleven stations to windward, varying from 8 to 26 miles, the sounds were also inaudible. It was found, indeed, that the sounds proceeding directly against the wind did not penetrate much beyond 3 miles.