BOM 



To put them together, you slide the 

 rings over the joiius placed as close as 

 possible, then by tightening- the thumb 

 screws you will have them firm together, 

 and may continue the tube to any length, 

 from one foot to whatever number is re- 

 quired 



Fig. 7. G, H, two steel punches or 

 drifts, to be placed on the he ad of the 

 copper bolt within the tube whilst driv- 

 ing. The blow given upon the punch 

 drives forward the bolt. The shortest of 

 them should be used first, and when driv- 

 en nearly to its head should be taken out 

 of the tube, and the longer punch applied 

 in its place. 



BOLTONIA, in botany, so called in 

 honour of Mr. James Bolton of Halifax, a 

 genus of the Syngenesia Polvgamia Su- 

 perflua Natural order of Composite Op- 

 positifoliae. Essential character: calyx 

 common subimbricate, with linear scales ; 

 corolla radiate ; germs compressed, ver- 

 tical ; down obscurely toothed, two-horn- 

 ed ; receptacle honey combed. There 

 are two species, viz. B asteroides, star- 

 wort-flowered boltonia; and B. glastifolia, 

 glaucous-leaved boltonia. Both these are 

 natives of America, and flower late in the 

 autumn 



BOMB, in artillery, a shell or hollow 

 ball of cast iron, having a large vent, by 

 which it is filled with gunpowder, and 

 which is fitted with a fuze or hollow plug, 

 to give fire by when thrown out of a mor- 

 tar, &c. : about the time when the shell 

 arives at the intended place, the compo- 

 sition in the pipe of the fuze sets fire to 

 the powder in the shell, which blows it 

 all in pieces, to the great annoyance of 

 the enemy, by killing the people or firing 

 the houses, &,c. They are now common- 

 ly called shells simply in the English ar- 

 tillery. 



These shells or bombs are of various 

 sizes, from that of 17 or 18 inches dia- 

 meter downwards. The very large ones 

 are not used by the English, that of 13 

 inches diameter being the highest size 

 now employed by them : the weight, di- 

 mensions, and other circumstances of 

 them, and the others downwards, are as 

 in the following table. 



BOM 



Mr. MuIIer gives the following propor- 

 tion for all shells. Dividing the diameter 

 of the mortar into 30 equal parts, then 

 the other dimensions in 30ths of that di- 

 ameter, will be thus : 



Diameter of the bore or mortar 30 

 Diameter of the shell . . . 29 

 Diameter of the hoi low sphere 21 

 Thickness of metal at the fuze 



hole 31 



Thickness at the opposite part 5 

 Diameter of the fuze hole . 4 

 Weight of shell empty . . _i_o d 

 Weight of powder to fill it . ^^Ld 



Where d denotes the cube of the di- 

 ameter of the bore in inches. But shells 

 have also lately been made with the me- 

 tal all of the same thickness quite around. 



In general, the windage or difference 

 between the diameter of the shell and 

 mortar is one sixtieth of the latter ; also 

 the diameter of the hollow part of the 

 shell is seven-tenths of the same. 



Bombs are thrown out of mortars or 

 howitzers; but they may also be thrown 

 out of cannon ; and a very small sort are 

 thrown by the hand, which are called 

 granadoes. 



BOMB chest, a kind of chest filled usual- 

 ly with bombs, sometimes only with gun- 

 powder, placed underground, to tear and 

 blow it up into the air, with those who 

 stand upon it. It was formerly set on 

 fire by means of a saucisse fastened at one 

 end, but is now much disused. 

 - BOMB ketch, a small vessel built and 

 strengthened with large beams for the 

 use of mortars at sea. 



BOMBARD, a piece of ordnance an- 

 ciently in use, exceedingly short and 

 thick, and with a very large mouth. 

 There have been bombards which have 

 thrown a ball of 300 pounds weight. They 

 made use of cranes to load them 



BOMBARDIER, a person employed 

 about a mortar His business is to drive 

 the fuze, fix the shell, load and fire the 

 mortar, and to work with the fire-workers 

 on all sorts of fire-works, whether for war 

 or rerreation. 



BOMBARDMENT, is the act of as- 

 saulting a city or fortress by throwing 

 shells into it, in order to set it on fire, or 

 otherwise demolish it. As one of the ef- 

 fects of the shell results from its weight 

 it is never discharged as a ball from a 

 cannon, that is, by pointing it at a certain 

 object: the mortars in England are fixed 

 at an elevation of 45. 

 BOMBARDO, a musical instrument of 



