SEPTEMBER 3, 1897. ] 
2. A contribution to the theory of plane curves: DR. 
L. WAYLAND DOWLING, University of Wisconsin. 
3. A Canadian discoverer of the non-Euclidean Geom- 
etry: PROFESSOR GEORGE BRUCE HALSTED, Uni- 
versity of Texas. 
4. Note on the Folium of Descartes: PROFESSOR 
ELLEN HAYES, Wellesley College. 
5. A geometrical locus connected with a system of 
coaxal circles: PROFESSOR THOS. F. HOLGATE, North- 
western University. 
6. On the solution of the map-color problem : PRO- 
FESSOR P. WERNICKE, State College of Kentucky. 
7. On the Riemann-Helmholz-Lie problem of the 
foundations of geometry : PROFESSOR H. B. NEWsoN, 
University of Kansas. 
MONDAY AFTERNOON. 
8. Quaternion invariantive operators: PROFESSOR 
JAMES BYRNIE SHAW, Illinois College. 
9. The geometry of some differential expressions in 
hexaspherical coordinates: DR. VIRGIL SNYDER, Cor- 
nell University. 
10. On certain differential equations of the second 
order allied to Hermite’s equation: PROFESSOR E. B. 
VAN VLECK, Wesleyan University. 
11. Concerning the cubic involution and the cubic 
transformation of elliptic functions : PROFESSOR OSKAR 
Boz, University of Chicago. 
12. The determination of the rational function in the 
reduction of the general Abelian integral to the sum of a 
rational function and a fundamental system of elementary 
integrals: DR. J. C. FIELDS, Berlin, Germany. 
13. On the reduction of hyperelliptic functions (p=2) 
to elliptic functions by a transformation of the second de- 
gree: D. J. I. HUTCHINSON, Cornell University. 
TUESDAY MORNING. 
14, Further researches in the theory of quintic equa- 
tions: Dr. EMoRY McCuLintTock, New York, N. Y. 
15. A theorem concerning the coefficients of lineal sub- 
stituting groups of finiteorder with n variables: PRo- 
FESSOR H. MASCHKE, Chicago University. 
16. On the commutator groups: DR. G. A. MILLER, 
Ann Arbor, Mich. 
17. Collineations in a plane with invariant conic or 
‘cubic curves: PROFESSOR H. S. WHITE, Northwestern 
University. 
TUESDAY AFTERNOON. 
18. Concerning regular triple systems: PROFESSOR 
E. H. Moore, University of Chicago. 
19. Theory of discrete manifolds : Mr. F. W. FRANK- 
LAND, New York, N. Y. 
20. Certain transformation problems of canonical 
equations of dynamics: DR. EDGAR ODELL Loyert, 
University of Chicago. 
SCIENCE. 307 
21. The true transition curve: Mr. P. H. Putte 
BRICK, Lake Charles, La. 
22. About siath power numbers whose sum is a sixth 
power: DR. ARTEMAS MARTIN, Washington, D. C. 
23. Preliminary report on alternate functions of com- 
plex numbers: PRorEssoR A. S. HATHAWAY, Rose 
Polytechnic Institute. 
General discussion of the following topics: 
1. The aceurate definition of the subject-matter of mod- 
ern mathematics. 
2. The vocabulary of mathematics. The possibility of 
correcting and enriching it by cooperative action. 
F. N. Cours, 
Secretary. 
CURRENT NOTES ON PHYSIOGRAPHY. 
ARTESIAN WELLS OF IOWA. 
A COMPREHENSIVE report on the artesian 
wells of lowa by W. H. Norton (Iowa Geol. 
Surv., VI., 1896, 113-428) brings clearly 
forward the favorable conditions there ob- 
taining for this important source of water 
supply. The paleozoic strata have a gentle 
southward inclination, and also a sag over 
the northern part of the State from the 
eastern and western boundaries towards 
a median line. Numerous water-bearing 
strata, or aquifers, occur, from the basal 
sandstone that lies on the buried hills and 
valleys of the Algonkian floor to the sand- 
stones of the coal measures. Cretaceous 
strata in the northwestern part of the State 
lead water away westward. Some impor- 
tant wells are supplied from aquifers in the 
glacial drift. ahree artesian wells were 
mentioned in thy State Survey Report for 
1870, and no sysjems of water works had 
been then constructed. About a hundred 
systems are now in operation, many of them 
depending on artesian supply. At certain 
points, where niany wells have been sunk, 
the first yield ‘has slightly decreased, as if 
the limit of local supply had been reached; 
but great stores of subterranean water re- 
main unexhausted beneath most of the 
State. 
FORESTS AND DESERTS OF ARIZONA. 
THE variation of climate with altitude 
