on the Solar Eclipse, November 29th, 1 826. 29 



and again for a longer period towards its termination. My 

 observations were made on the top of a house m the city :-im- 

 favourable, however, as the circumstances were, I believe the 

 results, as far as they go, can be relied on. 



I adopted a somewhat different method from that used by 

 Mr W • and one which appears to me capable of givmg more 

 accurate' results. It consists in having two thermometers, the 

 bulb of one pahited red, the other black: these bemg fixed 

 on one mounting with their bulbs detached, and exposed to- 

 aether to the influence of the sun's rays when eclipsed, and 

 when in its ordinary state, any difference in the quantity of 

 red ravs and of their heating power, in the two cases, would 

 he shown by a difference in the ratio of the risings of the two 

 thermometers in a given time upon exposure to the sun ihe 

 thermometers were graduated to quarters of centigxade de- 

 grees, and the diameters of their bulbs were, red 0-6 inch, 



black 0-55 inch. 1 1 j »^ 



The following is a statement of the results I was enabled to 

 obtain. The thermometers were held at a distance from sur- 

 rounding objects, and were as much as possible screened from 

 the wind, but not perfectly. 



Nov. 29. 

 A.M. \0^ 25"^. 



Clouds cleared off. Eclipse considerable. 



(!•) 



Minutes. 



Rise upon exposure to 

 the Sun. 



Red therm. Black therm. 



centigr. 

 0°'25 1 0°-5 



Ratio. 



red. :black. 



1 : 2 

 1 : 2 



Mean 1 : 2 



lO** ^S". Thick clouds. 



llh 20"". Clouds cleared off. Eclipse considerable. 



(II.) 



