292 GERAKDI REGNERI FOCKENS 



« Stars, the observations of which were suflicient in number , or lalten af projjcr spa« 

 <i sons of tbe year , to give room for any infcrence at all. Furliinatoly , howe\er, ilie 

 (t observations of the zenith dislances of Sirius were more in number, and, what is still 

 « of more consequeiice , in Ibis case, made in various, and sonie in opposite seasons of 

 « the year : aud , npon looking Ibem over , I was agreeably surprized to find a very 

 ci sensible diHerence in llie observations made at diflcrenl times, agrecing in direciion 

 « witb what a paralias ouglit to produce, the zenith distance of Sirius in July Coming 

 <( out no less thaii 8" greater than in ihe opposite season of the year , namrly in l)c- 

 « cember and January : the zenith distance also in Mareh and April being of an inter- 

 (f mediale quantity, as it ought to be : for, Sirius being in conjunction witb the sun in 

 « June and Jiily , it is evident he must be iben farlher from Ihe eartb llian in December 

 « and January , when be is in Opposition to the sun , and , cousequently , bis latitude 

 « aud declination, which are both soulh , must be less in the former case, llian in 

 rt the latter ; and iherefore , as be passes north of the zenith at the Cape of Good Hope , 

 <( liis zenith distance must be greater in the former season, than in the laller, as Iha 

 « observations indicate: but, in Marcb and April, when Sirius is in quadrature with 

 <, Ihe sun, and equally distant from the sun and earlh, bis apparent latitude and zenith 

 « distance must be the same as the true, or tbat whicb would obtain , if the earth was 

 « translated to the sun , and consequently , a mean between tbe zenith dislances in July 

 « and December , agreeably to the observations, " 



« I shall now lay before you tbe observations Ihemselves , logether witb tbe calcula- 

 « tions, whicb I have made of the values of Ihe parallax for each, the maximum being 

 « assumed 9" , which I find will best reconcile the observations with one another. '* 



Zenith 



