"Defsnpthn of . "Machine. 



therefore beyond. all doubt that porous wood, fqch as 

 that of the lime, the elder, &c. could be ftained much cafier. 

 Though the arfenical liver of fulphur from lime mav appear 

 fuperlluous, as the common, which is prepared from alkaline 

 falts and fulphur, can produce the fame effect, the above 

 procefs however is that which ought to be recommended. 

 This method of flawing may be considered as the beft, 

 becaufe it impregnates the wood with metallic particles, 

 gives it a hardnefs fufceptible of a fine polifli, and fecures 

 it from worms. The veffel employed for this purpofe mud 

 be either of porcelain, ftone ware, or glafs. 



XL Def crip lion of a new Diving l\Ia chine, proper for being 

 employed in Rivers, &c. By C. H. Klingekt. Ex- 

 tracted from the Author's Account of it, publilhed at 

 Breflau. 



JT O R feveral centuries mankind have employed their in- 

 genuity to devife means by which they might defcend into 

 the water, without danger, in order to fearch for funk 

 bodies; but all the inventions hitherto made for this pur- 

 pofe have never fully anfwered the propofed end, as they 

 have all been attended with inconveniences. Of thefe in- 

 ventions the beft known is the diving-bell ; but if a man 

 dtfeends in fuch a machine to a certain depth under water, 

 the air being condenfed in the bell in proportion as the 

 height of the column of water of equal diameter becomes 

 greater, he can breathe only for a fuort time; and the very 

 nature of the machine prevents him from moving about at 

 ple.tfurc, which is an object of the utmoft impo, V 



dtfire to obviate thefe difficulties induced the ) 



contrive a machine in which a man could not 01. I 



defcend at pleifure, but even at the depth of froi ) 



i! more under water, walk, breathe, and rn< 

 and he was fq far iucceftful that au experiment 1 



