Text Book of Gunnery, 1887H.M. Stationery Office, 1887 - 342 pages |
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Expressions et termes fréquents
8-inch howitzer accuracy angle of departure angle of descent angle of elevation approximately armour axis B.L. gun Ballistic Table Bashforth's bore breach bullets bursting charge calculation calibres carriage case-shot cast-iron causes centre chronograph column common shell compound armour correct corresponding curve cylinder deflection degs diagram diameter Diff difference direction distance effect elongated employed equation error experiments exterior feet field magazines fire flight fuzes given gives gravimetric density hoop stress hoop tension horizontal howitzer impact increased Krupp length less Lydd mean muzzle velocity obtained ordnance Palliser shot parapet penetration piece plane plates powder pressure Price projectile proportion radius range tables recoil remaining velocity resistance rifled rotation round scale screen secs ship Shoeburyness shrapnel shell sight square inch steel shells stress striking velocity Suppose tabulated tangent thickness tons trajectory trunnions tube twist weight whence wrought iron yards zone
Fréquemment cités
Page 118 - E, the magnetism of the electro-magnet is destroyed, and the spring f carries back the keeper, which, by means of the arm a, gives a blow to the lever b. Thus the marker m is made to depart from the uniform spiral it was describing. When the current is restored the keeper is attracted, and thus the marker m is brought back, which...
Page 15 - ... explode a charge, the crusher-apparatus, after due preparation, is first carefully screwed into its place, and the hole F closed. The cone in the firingplug is covered with the finest tissue-paper, to act as an insulator. The two wires LL, one in the insulated cone, the other in the cylinder, are connected by a very fine platinum wire passing through a small glass tube filled with mealed powder. Upon completing connexion with a DANIELL'S battery the charge is fired. The only audible indication...
Page 20 - ... the weight of a cubic foot in ounces." Major Makinlay, of the Royal Artillery, gives a better idea of what is meant by gravimetric density, but unfortunately confounds it with the air-space of the powder chamber, of which it is approximately a measure. According to the Woolwich Text-book, " the gravimetric density of a charge of powder in the chamber of a gun is the ratio of its weight to the weight of that volume of water which would fill the space behind the projectile in the gun. It is the...
Page 8 - Fire from guns with reduced charges, and from howitzers and mortars at all angles of elevation not exceeding 15°.
Page 6 - Quadrant Angle. — The angle which the axis of the piece, when laid, makes with the horizontal plane. It is termed quadrant elevation or depression according as the piece is laid above or below the horizontal plane.
Page 119 - Transverse grooves are cut at equal distances, something less than the diameter of the shot, as shown in the diagram. Staples of hard brass spring-wire (No. 14* or 15), are fixed with their prongs in the continuation of the grooves. Pieces of sheet copper A are provided, having two elliptical holes, the distance of whose centres equals the distance of the grooves. The pieces of copper A are used to connect each wire staple, as C, with its neighbour on each side. Thus, Fig.
Page 6 - Drift. — The constant deflection of a projectile from the plane of departure due to the rotation imparted by the rifling of the piece. It is sometimes termed derivation.