The lale Solar Eclipse. 237 



perfectly seen with the naked eye. The ring was complete, ex- 

 cept at the north-east quarter. The appearance at this time was 

 verv beautifu!. No change of temperature was perceptible by 

 the thermometer, and the diminution of light was not at all re- 

 markable. 



Paris, Sth Sept. — The weather yesterday was extremely fa- 

 vourable for the observation of the eclipse of the sun. This phae- 

 noinenon coukl add nothing to the precision of astronomical au 

 thorities, but it will furiiish the means of calculating the com- 

 parative longitudes of all the points of the globe in which the 

 beginning and end of the eclipse niav happen to be exactly de- 

 termined. We sui)join these two elements in sideral time as 

 marked at tlie royal ol)servatory of Paris : — 



Commencement .. .. llh. 45' 15" 



End .. .. .. 14 34 57 



A thermometer, exposed to the shade and towards the north, 

 fell in the interval between the commencement and middle of the 

 eclipse 2" ceutitirades ; another thermometer, inclosed in a me- 

 tallic case and exposed to the sun, fell during the same period 

 12** centigrades. 



On the Effect of the lale Eclipse of Sept. 7th, on the Heal 

 of the yitmosphere. Communicaled by Doctor T. Forster. 

 Sir, — I was desirous of ascertaining the precise degree in 

 which the late solar eclipse would depress the temperature, and 

 with this view made observations on two tliermoineters, one 

 placed in tlie sun, and the other in the shade. The day was 

 clear, and, except during the passage of a thin veil of cirrocu- 

 tnului, mixed with wane-cloud before the sun, (which was quite 

 transient,) no circumstance occurred to render the experiment 

 at all doubtful. The thermometer in the sun was placed on a 

 wall with a soiithern aspect. The instrument in the shade was 

 under a cool wall of the porch of the house, facing the north. 



In the sun, the thermometer at half past 1 1 o'clock stood at 

 84" of Fahrenheit's scale, and it continued rising till the eclipse 

 produced a depression, whicli I perceived to take place gradually 

 as the shadow of the moon intercepted the sun's rays. It must 

 be observed too, that after the eclipse was over, the thermometer 

 rose again, and that on ordinary occasicnis a perpendicular ther- 

 mometer rises to its greatest maximmn at about two o'clock in 

 the afternoon. 



The following is the result of the experiment: 



At 11 hours, 4 J min. Thermom. .. 92' 

 Noon .. .. ..94 



12'> 15' .. .. .. 94{ 



12 30 .. .. .. 921 



12h 



