BOL 
with long and thick heads, and struck into 
the uttermost bends of the ship to save her 
sides from bruises; and, ring bolts, used 
for bringing to of the planks, and those 
parts whereto are fastened the breeches and 
tackles of the guns. 
There are various inventions for driving 
both into ships, and others for drawing them 
out ; we shall describe one by Mr. R. Phil- 
lips, for driving copper bolts into ships, for 
which he received the gold medal from the 
Society of Arts, &c. in the Adelphi. The 
instrument employed for driving the bolts 
,, consists of a hollow tube formed from sepa- 
rated pieces of cast iron, which are placed 
upon the heads of each other, and firmly 
held thereto by iron circles or rings over 
the joints of the tube ; the lowest ring is 
pointed to keep the tube steady upon the 
wood ; the bolt, being entered into the end 
of the hole bored in the wood of the ship, 
and completely covered by the iron tube, 
is driven forwards within the cylinder by 
an iron or steel punch placed against the 
head of the bolt, which punch is struck 
by a mall ; and as the bolt goes farther into 
the wood, part of the tube is unscrewed 
and taken off till the bolts are driven home 
into its place up to the head. 
The tubes are about five inches in cir- 
cumference, and will admit a bolt of seven 
eights of an inch in diameter. 
References to Plate, Life Boats, Sfc. 
Fig. 4. A, the copper bolt, with one end 
entered into the wood previous to fixing the 
tube. 
B, a piece of timber or ship’s side, into 
which the bolt is intended to be driven. 
Fig. 5. C, C, C, C, the parts of the iron 
tube fastened together, ready to be put on 
the bolt A. 
D, D, D, D, iron or brass rings, with 
thumb screws placed over the joints of the 
tube to hold them firm together. 
E, E, E, E, the thumb screws, which 
keep the rings and tube firm in their pro- 
per places. 
F, two points formed on the lower ring, 
they are to stick into the timber, and to 
enable the tube to be held firm in its 
place. 
Fig. 6. Shews the separation of the parts 
of the tube, which is effected by slackening 
the thumb screws and rings. 
To put them together, you slide the rings 
over the joints placed as close as possible, 
then by tightening the thumb screws you 
will have them firm together, and may con- 
BOM 
tinue the tube to any length from one foot 
to whatever number is required. 
Fig. 7. G, H, two steel punches or drifts, 
to be placed on the head of the copper bolt 
within the tube whilst driving. The blow 
given upon the punch drives forward the 
bolt. The shortest of them should be used 
first, and when driven 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 Polygama Super- 
flua. Natural order of Composite Oppo- 
sitifoliae. Essential character : calyx com- 
mon subimbricate, with linear scales ; corolla 
radiate ; germs compressed, vertical ; down 
obscurely toothed, two-homed ; receptacle 
honey-combed. There are two species, viz. 
B. asteroides, starwort-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 mortar, &c.: about 
the time when the shell arrives at the in- 
tended place, the composition 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 commonly called shells, simply, in the 
English artillery. 
These shells or bombs are of various 
sizes, from that of 17 or 18 inches diameter 
downwards. The very large ones are not 
used by the English, that of 13 inches dia- 
meter being the highest size now employed 
by them : the weight, dimensions, and other 
circumstances of them, and the others 
downwards, are as in the following table. 
Diameter of 
the shell. 
Weight 
of the 
shell. 
Powder to 
fill them. 
Powder to 
burst them in- 
most pieces. 
13 inch 
lbs. 
195 
lb. oz. 
9 41 
lb. oz. 
7 8 
10 
89 
4 14| 
3 4 
8 
46 
2 
2 0 
of Royal 
14| 
1 li 
0 14 
4| Cohorn 
0 8 
0 7 
Mr. Muller gives the following propor- 
tion for all shells. Dividing the diameter 
of the mortar into 30 equal parts, then the 
