8o the force op

Beside the observations on the hygrometer it was remarked,that when atmosphere was very much loaded with vapour, thebore of the gun was so moist five minutes after the explosion,that the fixed nitre fell in deliquium; and the tow used incleaning it, was covered with a number of saline particles; buton a dry day no moisture could be perceived after an intervalof several minutes, and the tow came out almost unsoiled. Itresults from these experiments.

1. That the velocities of shot in very dry weatherexceed by'nearly -f the velocities, when the atmosphere isloaded with vapour.

2. That fine war powder produces in musquets thegreatest effect that can be obtained from a combinationof saltpetre, sulphur and charcoal. It is essential toadd, that with the fame kind of powder, the velocitieswere nearly equal in moist, heavy weather; under amean state of the atmosphere they varied about i £ inthe too; and in very dry weather, their differenceamounted to 4 in the 100.

168. The following experiments made with guns of dif-ferent lengths and calibres, under a mean state of the atmos-phere are a proof that fine war powder is the strongest.

Nature ofGuns.

Kind ofPqwder.

Drachma

* ,6- fFine War Powder 7

A t Æ 1 } Fowling Dittolength of bore. jx^ork Ditto

sFine War Powder

Rifled Carabine < Fowling Ditto

(.Fire-work Ditto

A Wall-piece carrying sFine War Powdera leaden bullet, in ^Fowling Dittoweight zi oz. (.Fire-work Ditto

A Musquet 3 ft. 6in. inlength of bore.

Weight ofPowder.

7

7

7

7

7

20

20

20 —

1 ^Fine War Ditto 7

Initial

velocity.

Feet.

I 3 qo

1367

1372

1956

1920

* 934 -

1956

1928

1923

1736

The experiments with a mortar made by Major Ronzxniin the month of August 1761, likewise prove the excellenceof fine war powder. The proportions of the mortar werevery exact; it was laid at 45 0 , fixed in an iron bed weighing61611?. and projected an iron shot 27 Ib. in weight, the

chamber