Defcription of an Invention hy the Author, for ilhijlrating his Ideas 

 refpeSting the Effects of the Eai'tKs diurnal Motion on the Clouds 

 in the Atinofphere. 



J\ FEW years fince, the eminent Chriftian Huygens, of Zuylichem, 

 paying me a vilit, our converlation chanced to tail on the diurnal 

 motion of the Earth ; whereupon I produced to him a glafs globe, 

 of my invention, which is reprefented in Plate XX. fig. 3. And, 

 upon my putting it in motion, he was fo much pleated with the ef- 

 fed, that I made him a prefent of a fmiilar globe : and having fince 

 frequently retleded on the lubjed:, I determined to publifli this my 

 invention, as illullratijig ray ideas of fome of the etFeCis produced 

 by the Earth's diurnal rotation on its axis, which the generality of 

 mankind do not attend to. 



I caufed fome glafs globes to be blown, about {extn or eight 

 inches diameter, and with a fmall neck or aperture. Having filled 

 one of thefe with water, I took fome red fealing wax, reduced to a 

 fine po\^'der, and put the fame into the globe. I then took a fmall 

 leaden bullet, which would pafs through the neck of the globe, and 

 boring a hole in it, I fixed to it a thread, and pafi'ed the fame through 

 a cork fitted to flop the opening of the glafs globe, the hole in the 

 cork being of fuch fizc that the thread, to which the bullet was fuf- 

 pended, might iHck in the cork at any length required ; then putting 

 the bullet into the globe, I caufed it, by means of the thread, to 

 hang at a fmall diftance from the bottom, flopping the mouth of the 

 globe clofe with the coik ; then, with fome twine, 1 made a kind of 

 net- work round the globe, twifiing the pieces of twine together, to 

 the length of about a foot beyond the neck of the globe. 



