Personal aiui Scientific News. 393 
reaches outward from the earth one or two hundred miles. He 
also showed that the prevalent notion as to the weight of the 
atmosphere, viz. that of a shell of mercury 30 inches in thickness 
surrounding the earth, is erroneous. He allowed the mass of 
the atmosphere to range between i- 1.200 and 1-10,000,000 of 
the mass of the earth. 
Walker prizes in Natural History. The Boston Society 
of Natural History offers annually two prizes for memoirs on 
certain subjects selected by a committee of that society. The 
first prize is sixty dollars, which may be increased to one 
hundred dollars, and the second prize does not exceed fiftv 
dollars. The competition for these prizes is not restricted, but 
is open to all. The memoirs presented in this competition are 
to be based on a considerable body of original and unpublished 
work, accompanied by a general review of the literature of the 
subjects. The subjects selected for 1900 are : "Stratigraphy 
and correlation of the sedimentary formations of any part of 
New England/' and "A study in paleozoic stratigraphy and 
correlation." The memoirs must be in the hands of the Secre- 
tary of the society on or before April i, 1900. The subject for 
1901 is "Monograph on any problem connected with or any 
g^roup belonging to the North American fauna or flora." 
Further information concerning these prizes and rules to be 
observed in competing for them may be obtained from the 
secretary of the society, Mr. C. F. Batchelder. 
Prof. Calvin of the Iowa geological surve^- has pre- 
sented his preliminary report upon the work of the year. The 
niain energies of the surve}^ have been directed as before to 
areal work though an increasing amount of subject work is 
being taken up. Professor Calvin devoted his attention to the 
Upper Coal ]\Ieasures and older drift in Page county and with 
Mr. Bain completed the work in Dubuque county. Prof. W. 
H. Norton of Cornell College worked in Cedar and Bremer 
counties on problems connected wath the Devonian and 
Silurian and the lowan drift. Prof. J. A. Udden carried his 
work south r.s far as to cover Louisa county. He connected 
here with Mr. Savage who was making preliminary surveys in 
Henry county. In Marion county Prof. B. L. Miller of Penn 
College, filled in an important gap in the previous mapping. 
In the northwest professor Macbride continued his studies of 
the Wisconsin drift, covering Dickenson and. Osceola counties 
and devoting especial attention to the lakes of the region. West 
of him Mr. F. A. Wilder, of Des Moines, connected his work 
with that already completed farther south by surveying Lyon 
and Sioux counties, devoting especial attention to the puzzling- 
extra- Wisconsin drift of the region. In the north central 
])ortion of the strte Mr. Ira Williams carried professor Calvin's 
