33® ^-^ the Ffizuers of the pifmatlc Colours 



might be admitted, a white fmokcd glafs near the eye. Better 

 than No. j^ ; but the green glafs' cr?.cked. 



No. 17. A very dark preen and white fmoked glafs, as 

 before. Very diftinft, but the green glafs cracked in about 

 Cx or feven ruinutes. 



Nq. 18. A dark blue glafs, as in No. 15, and white fmoked. 

 This was diflindl:, and no heat came to the eye. The fun 

 appeared ruddy. 



No, 19. A dark blue ?nd a yellaw glafs, clofe together, as 

 in No. l^, ^nd a, white fmoked one as before. This was not 

 cliftina:,' 



No. 20. A purple g'r.fs, as in No. 15, with a white fmoked 



rne. This gave the fun of a deep orange colour, approaching 



tofcarlet. It was not dinipft. .. ' 



No. 21. An orange glafs, as in >Jo. 15, with a white 



fmoked one, Thp colour of the fun was too red. 



No, 22. A white fmoked glafs, as in No. 15, without any 

 other at the eve. This gave the fan of a lieautifui orange 

 colour; but diftinctnefs uastotalK' deltrnyed. 



No. 33. The heat near. the fiiiall fpeculuin being fiill too 

 powerful for the glafTcs, I had a blMeifli dark green glafs madj? 

 oif.H pope" diameter to be inclofed between thu two eye- 

 glailes.of ^ d'Hvble fcve-piece. All glafs I knew would Itop 

 fofiie heat ; and was therciorc in hopes that the interpofition 

 of this eye-glafs would temper the ravs, foas in fomemeafur^ 

 to pro*e^t the coloured glafs. In theufual place near the eye, 

 I pu' tw'> white giafles, with a thin coat of pitch between 

 them. Thele glaiTes, when looked through by the natural 

 eye, eive the fun of a red pol'^ur; I therefore entertained no 

 great hopes of their application to the telefcope. They 

 ilarkcned the fun not funiciently j and when the pitch was 

 thickened difiip'''tnefs was wanting. 



No. 24. The fame glafs between the eve-glaflcs, and a 

 dark green fuioked olafs at the eye; very dTtincl This ar- 

 rangement is preferable to that of No, 15 ; after fome confi- 

 derabie time, however, this glafs alio cracked. 



No. 25. 1 placed a very dark green glafs behind the fecond 

 f ye-glafs, that i.t n/fght be {})ellercd by both glafles, which in 



■ my 



