ARTILLERY. 



countries, which have no reinforces or in- Park, as a trophy of war, brought from 

 crease of thickness at the muzzle ; a very Egypt by the victorious troops command- 

 beautiful one of this description of brass, ed by General Lord Hutchinson. 

 of a large size, now lies in St. James* 



The following Table shews the dimensions of heavy, medium, and light brass gtms> 

 in thirty second parts of their respective calibres. 



C At the breech and commencement of 



Thickness of J the first reinforce 



metal. ] End of the first reinforce 



(JMuzzle astragal 



C Diameter . 



2 Length 



From the extremity of the base ring to 



that of the breech mouldings . . . 

 From the end of the breech mouldings 



to the centre of the button .... 

 Breadth f the ovalo, or quarter round 



C Of the button 



Diameter-} Of the neck 



C Of the last fillet 



Trunnions. 



Case able. 



Heavy. 



33 

 26 

 17 

 32 

 32 



12 



SO 

 4 

 32 

 26 

 48 



Medium. Light. 



32 22 



25 

 16 

 30 

 30 



10 



3 



26 

 22 

 44 



16 

 10 



20 

 24 



24 

 3 



26 

 20 

 36 



In heavy and medium brass guns, the 

 first and second reinforces are similar 

 frustrums of right cones; and conse- 

 quently, when produced, their outlines 

 will be parallel to each other, and are dis- 

 tant one-sixteenth part of the calibre. 

 The exterior diameter of the piece is also 

 diminished by that quantity, and its out- 

 line is drawn to the muzzle astragal. ^ 



In light guns, the length of the piece 

 must be divided into eighteen equal parts, 

 ef which 



5 parts are taken for the breech and 

 first reinforce ; 



4 parts for the second reinforce ; 



9 ... for the chase ; 



2^ . . for the length of the muzzle; 



^ part for the diameter of the neck. 



The axis of the trunnions are 8 parts 

 from the breech, and half a calibre below 

 the axis of the piece. The position of 

 the trunnions of heavy and medium brass 

 guns is as three-sevenths of the length of 

 the piece, from the extremity of the 

 breech, and half a calibre below the axis 

 of the piece, reckoning to their centres. 

 The diameter of the trunnions are each 

 one calibre, and their length the same, 

 allowing for the projection of the second 

 reinforce ring; their faces are parallel 

 to the axis of the piece. The trunnions 

 of medium and light brass guns have 

 shoulders, which are a tenth of the dia- 

 meter of the trunnion in breadth, and of 

 sufficient depth to clear the projection of 

 the second reinforce rings. 



The vent fields are one-seventeenth of 

 the breech and first reinforce. 



The chase girdles are one-fourteenth 

 part of the chase. 



The length of the muzzle is equal to 

 the diameter of the second reinforce ring 

 in heavy guns ; and in medium guns, one- 

 seventh of the length of the piece. The 

 diameter of the swell of the muzzle is 

 equal to the diameters of the second rein- 

 force rings. 



The bottom of the bores of heavy brass 

 guns is a plain surface, meeting the sides 

 in a small arc described with the radius 

 of l-24th of a calibre ; in medium and 

 light guns they are hemispherical, and 

 their vents form an angle of 75 degrees 

 with the axis of the piece ; making in 

 light guns one-third of the calibre, and in 

 medium one-fourth of the calibre, from 

 the extremity of the bore. 



The vents of heavy guns are a fifth of 

 an inch in diameter. 



In medium and light guns there Is a 

 portion of metal beneath the neck of the 

 cascable, for receiving the loop of the 

 elevating screw. The lower part of it is 

 the arc of a circle, described with a radi- 

 us equal to the semidiameter of the neck; 

 of the position of the centre is one-fourth 

 part of the distance from the extremity 

 of the breech moulding to that of the but- 

 ton, and is one -fourteenth of the diame- 

 ter of the neck below it. 



Medium and heavy guns are cast with 

 dolphins, by which they are occasionally 

 suspended, and they consequently should 

 be placed over the centre of gravity of 

 them, or rather so that the breech may 

 preponderate in a small degree. 



