108 REPORT OF THE SECRETARY. 



In the case of the moon, as you have shown, about three-fourths of the deflec- 

 tion is due to the radiations of the moon itself, whose surface is shghtly warmed by 

 the solar rays, the remaining one-fourth being due to direct reflection of solar rays; 

 but in the case of the daylight sky it Avas found here that the quality of the radia- 

 tions was almost the same as that of the rays direct from the sun, so that the heat- 

 ing of the bolometer in this case is almost solely l)y direct reflection and not from 

 primary radiations due to first warming of dust or other particles in the air. 



The imjiortant result of a comparison of the ra<liations of the inner corona, the 

 full moon, and tlie daylight sky somewhat remote from the sun is that while the 

 three are roughly of c(iual visual brightness, the corona is effectively a cool and far 

 from intense soun-e, while the moon and the sky are effectively warm and many 

 fold richer in radiation. Hence it would a])pear jilausible to suppose that the corona 

 merely sends out visible rays and that its light is not associated with the great pre- 

 ponderance of longwave-length rays proper to the radiation from bodies at a high 

 temiierature. If this ])e so, the coronal radiation might be compared with that from 

 the positive elecitrical distiharge in vacuum tul)es, in whicli, as researches of K. Ang- 

 strom and R. W. "Wood have shown, there is neither an infra-red spectrum nor a 

 high temperature. I am not sure whether this analogy can safely be carried further 

 to exjilain the coronal constitution, but it may be recalled that the earth has in tiie 

 aurora an electrical phenomenon of this nature; that the coronal streamers appear 

 not unlike an electrical discharge; that the observed polarization of the coronal light 

 is perhaps not necessarily by reflection, for polarization may be otherwise caused, as 

 by the emission or absorption of bodies of peculiar internal structure, or even by 

 magnetic influences, as in the Zeeman effect; that the corona does not seem to grow 

 more red as it rece<les from the sun, as we should expect incandescent dust to do, 

 and finally the evi<lence of conmal spectroscopy seems not inconsi.'ttent with the 

 hypotliesis of a glow electrical discharge. 



7. With vixual telescopes. — I understand that in yom- own view, with the 5-inch equa- 

 torial, the inner corona appeared to have a much less minutely divided structure than 

 that of 1878, and to be chiefly noticeable in its equatorial as opposed to its polar 

 extensions. Prominences were plainly seen, and especially one large one at the 

 southwest limb. 



INIr. Child, with the (3-inch, being the artist of the party, made sketches from which 

 he later prejjared in pastel color a representation of the corona and prominences 

 strikingly in accord with the photographs which were sul)sequently developed. 



Rev. Father Woodman, with the 3i-inch, received impressions similar to those of 

 the other visual observers. 



S. Times of contact. — Mr. Putnam, a part of whose duty it was to direct the giving 

 of signals, observed first, second, and fourth contacts, but missed the third in conse- 

 quence of being hindered by directing the last signal. 



His observations, reduced to seventy-fifth meridian mean time, are as follows: 



h. m. s. 



Firstcontact 19 36~ 19.7 



Second contact 20 45 15.5 



Fourth contact 22 05 37.3 



Father Woodman's observations are as follows: 



h. VI. s. 



First contact 19 36 21 



Second contact 20 45 16 



Third contact 20 46 47 



Fourth contact 22 05 26 



The photographic contact camera furnished apjiarently excellent records of first, 

 third, and fourth contacts. These have not been finally reduced, but it is found 



