AERIAL OLOBF.S. 239 



the bottom excepted ; which, as already said, must be of wood. 

 The chamber for the powder must be pierced obliquely, with a 

 small gimblet ; so that the aperture corresponding to the aperture 

 of the metal mortal, the fire applied to the latter may be communi. 

 cated to the powder which is at the bottom of the chamber, imme- 

 diately below the globe. By these means the globe will catch fire, 

 and make an agreeable noise as it rises into the air ; but it would 

 not succeed so well, if any vacuity were left between the powder 

 and the globe. 



A profile or perpendicular section of such a globe is represented 

 by the right-angled parallelogram, the breadth of which is nearly 

 equal to the height. The thickness of the wood, towards the two 

 sides, is equal, as above said, to the twelfth part of the diameter of 

 the globe ; and the thickness of the cover is double the preceding, 

 or equal to a sixth part of the diameter. The height of the cham- 

 ber, where the match is applied, and which is terminated by a semi- 

 circle, is equal to the fourth part of the breadth ; and its breadth 

 is equal to the sixth part. 



We must here observe that it is dangerous to put wooden covers 

 on aerial balloons or globes ; for these coters may be so heavy, as 

 to wound those on whom they happen to fall. It will be sufficient 

 to place turf or hay above the globe, in order that the powder may 

 experience some resistance. 



The globe must be filled with several pieces of cane or common 

 reed, equal in length to the interior height of the globe, and charged 

 with a slow composition, made of three ounces of pounded gun* 

 powder, an ounce of sulphur moistened with a small quantity of 

 petroleum oil, and two ounces of charcoal ; and in order that these 

 reeds or canes may catch fire sooner, and with more facility, they 

 must be charged at the lower ends, which rest on the bottom of the 

 globe, with pulverised gunpowder moistened in the same manner 

 tvith petroleum oil, or well besprinkled with brandy, and then 

 dried. 



The bottom of the globe ought to be covered with a little gun- 

 powder half pulverised and half grained ; which, when stt on fire, 

 by means of a match applied to the end of the chamber, will set 

 fire to the lower part of the reed. But care must have b-en taken 

 to fill the chamber with a composition similar to that in the reeds, 

 or with another slow composition, made of eight ounces of gun- 



