TRANSIT OF MERCURY. Q 



1 1'* 28'. The planet havfng advanced towards the pre- Obfervations of 

 ceding limb of the fun, it was now time to attend to the ap- "^^^ *=""'^'^^^' 

 pearances of the interior and exterior contads. 



1 1'' 32'. 10-feet reflector. The whole diflc of Mercury is as Not the leaft 

 fharply defined as poffible ; there is not the leafl: appearance ^^^j'^f^^"^ 

 of any atmofpheric ring, or different tinge of light, vifible about Mercury. 

 about the planet. 



1 ]^ 37'. Appearances remain exadly as before. 

 1 1*" 42'. The fliarp termination of the whole mercurial difk, 

 appears to be even more ftriking than before. This may be 

 owing to its contraft with the bright limb of the fun, which, 

 having many luminous ridges in the northern zone, is remark- 

 ably brilliant about the place of the planet. 



11'' 44'. I was a few moments longer writing down the -At the interior 

 above than I fhould have been, to fee the interior contact ^o to^^jQ^ gi^l^g^.'^^ 

 completely as I could have wiflied ; however, the thread of the fun's limb 

 light on the fun's limb was but juft breaking, or broken ; but ^^l^ercJ'^ °^ 

 no kind of diftortion, either of the limb or of the difk of Mer- 

 cury, took place. 



The appearance of the planet, during the whole time of its nor dnring the 

 emerging from the fun, remained well defined, to the very ^"'^''g'^g "O'' 

 laft. ^ '""'^' '* 



The following limb of Mercury remained (liarp till it reached 

 the very edge of the fun's dilk; and vaniflied without occa- 

 fioning the fmalleft diftortion of the fun's limb, in going off, 

 or fufl^ering the lead alteration in its own figure. 



As foon as the planet had quitted the fun, the ufual appear- 

 ance of its limb was fo inftantly and perfectly reftored, that not 

 the leaft trace remained whereby theplaceof its difappearance 

 could have been diftinguiflied from any other adjacent part of 

 the folar dillv. 



It will not bearaifs toadd, that very often, during the tranfit. No figns of 

 I examined the appearance of Mercury with a view to j^g ^n oblate figure, 

 figure, but could not perceive the lead deviation from afphe- 

 rical form ; fo that, unlefs its polar axis fhould have happened 

 to be fituated, at the time of obfervation, in a line drawn from 

 the eye to the fun, the planet cannot be materially flattened at 

 its poles. 



OBSERVATIONS 



