Horsford.] 258 fJ^'^- 



physical experiments with his improved pyrometer, and re- 

 searches into the proportion of draft to the surfaces of fuel. 



A letter was read from Professor E. N. Horsford, dated 

 Cambridge, July 10th, 1866, giving an account of a remark- 

 able rainbow as follows : 



On Sunday the 8th instant, we witnessed here a rainbow of rare 

 brilliancy and multiplication. It was at the close of a severe thun- 

 dergust, accompanied by a violent shower just before sunset. The 

 arch was maintained throughout, but in some parts less brilliant than 

 in others. The part extending some forty degrees on either side of 

 the summit, rested on a luminous, fleecy cloud as a background, con- 

 trasting singularly with the darker clouds below. Over all this por- 

 tion it was easy to distinguish the primary and secondary bows. In 

 short sections there was a duplicate secondary bow, or at least the 

 red division. This was novel to me. But within the primary bow, 

 in which all the colors were wonderfully brilliant, there were in some 

 short sections no less than five repetitions of the red division of the 

 spectrum. Each succeeding one was fainter from without inward, 

 and less remote from its nearest outer companion. The whole width 

 of the five red divisions was scarcely twice the width of the primary 

 bow. Pouillet speaks of a third and fourth bow, but here were no 

 less than eight. 



Donations for the Library were announced from the Geo- 

 graphical Societies of St. Petersburg and Paris ; the Bureau 

 des Mines ; the Astronomical Society of London ; the Bos- 

 ton Natural History Society, and the American Academy; 

 the Massachusetts and New Hampshire Historical Societies ; 

 Harvard College ; Professor Horsford ; the New York Ly- 

 ceum ; the Polytechnic College at Philadelphia ; Medical 

 News ; Friends' Freedmen Relief Association ; the Union 

 League ; Ohio Mechanics Institute ; St. Louis Academy of 

 Sciences ; and the Superintendent of Public Instruction in 

 California. 



A copy of the Catalogue of the books of the Society, part 

 II, just published, was laid upon the table for examination by 

 the members. 



The decease of a member, Dr. Paul Beck Goddard, July 

 oth, aged 57, was announced by Professor Kendall. 



