h'lfe of Jojeph ToaJdo. 257 



fiifficient to receive a fmall heniifphere of glafa, and to allow 

 the heniifphere to rife a Htllc in its fmall chamber, but not 

 to turn over in it. The vipper piece of the internal tube is 

 then thruft home to the place in which it is to remain, and 

 the glafs heniifphere introduced, with its plane incumbent on 

 the upper end of the lower pieceof the internal tube, which is 

 ground perfecllv flat, as is alfo the plane of the heniifphere. 

 From the condruclion, it is obvious that, by the upward 

 preflure of any gas, the glafs hemil'phere may be raifed fo as 

 to allow the aeriform fluid to pais into the adaptor, but that 

 there can be no return of anv thing into the receiver even 

 when a partial vacuum takes place in it ; and the greater the 

 excefs of the expanfive force or ])rclTure exerted at any time 

 in the adaptor over that maintained in the retort and receiver, 

 the clofer does the valve become. 



Fig. 3. two adaptors, Is. and B, ground to fit into each other, 

 and alfo to fit into C of tig. t. Any number may be fitted 

 to each other in the fame manner. By this apparatus liquids 

 rnav be hiffhiv imprc^inated with the cafeous products evolved 

 during diflillations. The bent tube '1' is for the purpofe of 

 conveying the fuperabundant gas to a chimney or to a pneu- 

 matic apparatus. 



Fig. 4. improvement in the mode of fitting the glafs tubes 

 in a VVoulfe's apparatus. This has already been fufficicntly 

 explained. 



XLIII. Life of JosKVH ToALDO, Profe/for of AJirommy 

 and Meleorology at Padua. 



J 



OSEPH TOALDO, whofe merit as a philofopher and 

 nioteorologift is well known in all the civilized countries of 

 F.urope, was born on the nth of July 1719 at San Lorenzo 

 di Pianezza, a fmall village near Maroltica, at the foot of 

 the Alps, in the valleys of Vicenza. The firft part of his 

 education he received from various eeclefialtics, who gave 

 him an early talle for tlie fciences, and accuftonicd him to 

 diligence and ajjplication. In the year 173 ^ he was fent to 

 the feminary uf Padua, where he Itudied Latin, rhetoric, 

 philofophy, and theology, but in particular the mathema- 

 tics, ilere he took the degree of doftor of thcolog)', and 

 was deftined for the place of a teacher in the fame inftitutiou 

 in which he had been inllruclcd. About this period he 

 bcrrnn to diftinguifli himfelf as a writer. The firlt literary 

 labour he engaged in was a new edition of the works of Ga- 

 Uieo, to whipjj he added variqus fragments never before pub- 

 VoL.XI. K iifhed 



