SHELL 



5345 



SHELL 



carved into cameos, and the large shells are 

 used as ornaments. They can be seen from 

 the glass-bottomed boats near Catalina Island, 

 where about $40,000 worth are annually sold. 

 Pulverized conch shells are used in the manu- 

 facture of porcelain, and many of the large and 

 beautiful varieties are prized as ornaments. A 

 flat, thin shell found in the Pacific and Indian 

 oceans, so transparent that print can be read 

 through it, is commonly used in the Philippine 

 Islands as a substitute for window glass. In 

 Africa and India, the small cowries furnish a 

 ready-made currency requiring only to be strung. 

 They are the only currency of the natives of 

 the Sudan in Africa, and traffic in these shells 

 on the west coast of Africa has made fortunes 

 for the Dutch and English traders, who ex- 

 change them for palm oil and ivory. A scal- 

 lop shell worn by the pilgrims of the Middle 

 Ages, to show they had crossed the sea to the 

 Holy Land, came to be known as pilgrim shell. 

 These shells were frequently adopted as her- 

 aldic devices by families whose ancestors had 

 made the pilgrimage. E.B.P. 



Related Subjects. For further information on 

 the subject of shells the reader is referred to the 

 following articles, many of which are illustrated : 

 Abalone Mollusks 



Cameo Mussel 



Clam Nautilus 



Conch Oyster 



Cowrie Scallop 



Mother-of-pearl Snail 



SHELL, a term used collectively to describe 

 the various projectiles fired from big guns. 

 There are many different forms of shell, .vary- 

 ing in shape, size and composition, according 



which scatter when the charge is exploded by a 

 fuse set for this purpose. Shells are now usu- 

 ally made of steel or copper. 



The shells used by armies on land are quite 

 different from those used in naval warfare. On 

 land it is seldom that the shell is required to 

 penetrate any metal defenses, except when per- 

 manent forts are attacked, so the metal of 

 which they are composed does not go through 

 the hardening processes necessary for shells in- 

 tended to pierce the armor plate of vessels. 



In the War of the Nations, beginning in 1914, 

 the shell chiefly used was shrapnel, except when 

 the biggest guns were battering down forts by 

 sheer weight of metal. The smallest shrapnel 

 shell is that used in field guns, which in the 

 French, German and British armies are guns 

 of approximately 3-inch caliber. The weight 

 of the shell varies according as it is a high- 

 or a low-velocity shell. A gun will send a light 

 shell a great distance at high velocity, and it 

 will send a heavier one perhaps as far but not 

 as quickly. The French and German high- 

 velocity shells weigh sixteen pounds. The Brit- 

 ish usually fire from the 3-inch gun a shell of 

 eighteen and one-half pounds weight for field 

 artillery and thirteen pounds for horse artil- 

 lery. The shell contains from 250 to 363 bul- 

 lets, which are discharged by the bursting of 

 the shell. The charge for firing a shell of six- 

 teen pounds is 4.61 pounds of explosive con- 

 taining forty per cent nitroglycerine (these fig- 

 ures referring to one of the latest Kruppguns). 

 The following table illustrates the weight of 

 shell and weight of charge fired from six pat- 

 terns of Krupp ordnance: 



to the purposes for which they are intended. 

 Ordinarily, a shell is a hollow projectile filled 

 with explosive powder, or powder and bullets, 



The following table shows the same particu- 

 lars concerning ordnance in use by the United 

 States navy: 



Figures as to rapidity of fire are not available, but it may be assumed that the rate of fire is at 

 least equal to that of European guns of the same caliber. 



335 



