4.86 BoEDDiCKEE — On Lunar Radiant Heat. 



4. As in 1884, the differences of the consecutive readings of the galvanometer 

 were taken together in groups of ten, and the mean of each group vs^as assumed to 

 represent the heat-effect corresponding to the time of the sixth of the eleven 

 readings which furnish the ten differences. Owing to the observations forming 

 an all but uninterruiDted series, this grouping was proceeded with from difference to 

 difference, so that the epochs of the heat values vary generally speaking by O'S" 

 sidereal time only. Thus each reading was submitted to exactly the same treat- 

 ment; and 473 values for the lunar heat were obtained. Of these 446 were 

 available for the construction of the final heat curve. The first value, namely, 

 corresponding to Z^ 22"7" (or l"" 4*2°' before the first contact with the penumbra) 

 was excluded, as the Moon was still very low at that time, and situated, as seen 

 from the Observatory, over the town of Parsonstown, so that but little reliance can 

 be placed on it. And further, the values recorded during totality were excluded 

 (as mentioned above) because the thermopiles were obviously not fully exposed to 

 the lunar rays. 



It may here be remarked that in the preliminary notes of these heat-observa- 

 tions which I communicated to Nature (No. 953, vol. xxxvii., February 2, 1888), 

 and to the Asironomische Naehrichten (No. 2828, February 25, 1888) the observa- 

 tion of B"" 22'7'" was not excluded. The values given in the latter jom-nal, being 

 expressed in per cents, of the now excluded value, have, consequently, all to be 

 corrected according to the present detailed publication. 



5. The following Tables give the eclipse-observations in full. Their arrange- 

 ment agrees strictly with Table I. in these Transactions for October, 1885, p. 323, 

 containing the results of 1884. Any necessary explanations will be found on 

 pp. 501 and 502. 



