VOL. LVIIl.J VHILOSOPHICAL TRANSACTIONS. 525 



the signs, the upper take place both with ?S and £1 when, in the forenoon ob- 

 servation, a is not > 270° — b — e, or in the afternoon a >• 270° -\- b; for in 

 these cases the lower signs obtain. Note also that sin. s := — — '— ; and v = e 

 + r, where the sign + takes place in the forenoon observations, and — in the 

 afternoon, unless a be < go° — /;, and a >■ 90° + b. Also, for v is to be taken 

 its excess above 1 80°, whenever a >■ 270° — b — e, or a >■ 90° + b. 



^ V. Now the observations by which, on the foregoing principles, the sun's 

 parallax is to be investigated, will be found in the following table; where in the 

 column titled contact 1 is contained the total immersion, in contact 2 the begin- 

 ning of the emersion, and in contact 3 the total emersion. The longitudes of 

 places, in column 3, are counted from the meridian of Paris. The 1st column 

 contains the names of the places themselves, and the 2d column the names of 

 the observers. 



^ VI. The next table shows the different 

 computed from the for'igoing observations. 



horizontal parallaxes of the sun, as 

 which have been deduced both by 



