Stoddor.] 



340 



[December 11, 



In 18G4 Mr. R. C. Greenleaf resolved the highest band on his dif- 

 fraction plate — the same number of lines as the highest of Sullivant 

 and Wormley's ggjpj^ — with a Tolles's ^. There may be, perhaps, 

 some question as to this, but the next year he unquestionably saw the 

 lines clearly and unmistakably with a Tolles's ^^g- Thus accomplish- 

 ing with a Jj what had — so far as appears by the records — up to 

 that time never been done, with any instrument of any power then 

 made, and which has not been exceeded by any made since, until 

 within a few weeks. 



INIr. R. C. Greenleaf and myself have been trying a test plate of 

 nineteen bands, the same as the one used by Schultz, with the follow- 

 ing results : — 



^tAts- of a Paris line= 



f 1st. -3 



■ 16860 



1 



■ 22480 



■ 1 



■ 44960 



1 



56200 



. 1 



■ "67622 

 . 1 



" V873T 

 . 1 



" gooTT 

 1 



• 96 23 4 

 1 



'lOiTTT 



. 1 



"ToTieT 



- _ 1_ 



"112660 



«i 



15th. 

 20th. 

 25th. 

 30th. 



CO t-, 



-J 



j; s- 



With obUque kerosene or gas light, condensed only by the concave 

 mirror, the bands have been resolved as follows: — 



Objectives. Eye-piece. 



Wales, ^ ang. aper. 140° A 



" " (by dayhght) B 



Hartnaeh's immersion. No. 10, 



ang. aper. 155° to 160° 

 Tolles's immersion, J^, ang. 



aper. 170° 

 Tolles's immersion, ^, ang. aper. 



1 70°. By R. C. Greenleaf 

 Hartnaeh's No. 10=y\, ang. 



aper. 155° to 160°. By R. 



C. Greenleaf B 



B 

 B 

 B 



Diameters. 

 475 



1062 



550 



1150 



Band resolved. 

 8th. 

 11th. 



10th. 



15th. 



19th. 



15th. 



