236 WATER GLOBES. 



shall here describe. Among these are globes and fire balls ; some of 

 which are intended to produce their effect in water ; others by 

 rolling or leaping on the ground ; and some, which are called 

 bombs, do the same in the air. 



SECTION I. 



Globes which burn on the Water. 



THESE globes, or fire balls, are made in three different forms ; 

 spherical, spheroidal, or cylindrical ; but we shall here confine 

 ourselves to the spherical. 



To make a spherical fire ball, construct a hollow wooden globe 

 of any size at pleasure, and very round both within and without, 

 so that its thickness may be equal to about the ninth part of the 

 diameter. Insert in the upper part of it a right concave cylinder, 

 the breadth of which may be equal to the fifth part of the diameter ; 

 and having an aperture equal to the thickness, that is, to the ninth 

 part of the diameter. It is through this aperture that the fire is 

 communicated to the globe, when it has been filled with the proper 

 Composition, through the lower aperture. A petard of metal, 

 loaded with good grained powder, is to be introduced also through 

 the lower aperture, and to be placed horizontally. 



When this is done, close up the aperture, which is nearly equal 

 to the thickness of the cylinder, by means of a wooden tompion 

 dipped in warm pitch ; and melt over it such a quantity of lead 

 that its weight may cause the globe to sink in water ; which will 

 be the case if the weight of the lead, with that of the globe and the 

 composition, be equal to the weight of an equal volume of water. If 

 the globe be then placed in the water, the lead by its gravity will 

 make the aperture tend directly downwards, and keep in a perpen- 

 dicular direction the cylinder, to which fire must have been pre- 

 viously applied. 



To ascertain whether the lead, which has been added to the globe, 

 renders its weight equal to that of an equal volume of water, rub 

 the globe over with pitch or grease, and make a trial, by placing 

 it in the water. 



The composition with which the globe must be loaded, is as 

 follows: to a pound of grained powder, add 32 pounds of salt, 

 pttrc reduced to fine flour, 8 pounds of sulphur, 1 ouuce of scrapings 



