Proceedings of the Academy. 273 



As Corresponding members : 



Dr. C. C. Abbott, Trenton, New Jersey. 

 Alford Paine, S. T. D., of Hinsdale, 111. 



As Honorary member, 



Prof. Spencer Baird, M. D., LL. D., of Washington, D. C. 



Prof. Allen, chairman of the committee appointed to see about securing 

 rooms for the Academy, reported that the rooms of the Railroad Commis- 

 sioners could be secured in December. The report accepted, and the com- 

 mittee continued. Prof. Allen then read a paper on " Early Form of Land 

 Tenure." 



Dr. Falk made extended remarks on Prof Allen's paper, and gave a review 

 cf the feudal relations in Germany. 



Prof. McMurphy read a paper on " Rotation as a Factor of Motion." 



The President then read the following communication from Captain 

 ISTader, C. E., on " The Balloon in Meteorology." 



Madison, Wis., June 30, 1877. 

 Dk. p. R. Hot, Racine, Wis.: 



Dear and Respected Sie: Your very kind note of invitation of 

 the 7th instant was duly received, and while I regret very much 

 that I shall be unable to partake of the proffered hospitality of the 

 people of Racine, I feel very thankful for your kind remembrance. 



My duties here render my time uncertain, and occupy my atten- 

 tion so much that I shall not be able to attend the meeting, which 

 no doubt will be pleasant and instructive. I shall be unable to 

 produce anything in time. I was preparing a letter to you, when I 

 received your note, on a subject which may be interesting, and 

 which I will now give you as briefly as possible. 



It is but a short time since an idea occurred to me which I be- 

 lieve to be novel, and perhaps of scientific import, and should you 

 consider it of sufficient importance, I beg you would please present 

 the same for discussion at the meeting. 



The object is to explore the atmosphere, so far as may be prac- 

 ticable, without the risk of life and limb. This I propose to do in 

 the following manner: In the first place, I resort to a gas balloon 

 to carry up my apparatus, and since there is no danger of any irre- 

 parable damage, the same may be constructed as light as possible, 

 even frail, I may say; and since the charge is not required to endure 

 very long, small leaks need not be noticed, and I believe such a 

 balloon may be constructed at a nominal cost. 



Each cubic foot of gas of specific gravity, say 0.6, will displace 

 about 530 grains of air, and deducting its weight, 32 grains, will 

 18 



