30 PHILOSOPHICAL SOCIETY OF WASHINGTON. 
TABLE I. 
Membership and Attendance of the Philosophical Society, by Years. 
22 ap | $2 
aA GIN Ge Ae a Ue 
Z --o LE om no | 
if z=) o& "82 ? DS New societies or 
eee 3 5 ae oS a Bre ganized. 
E 255 pos o4 
> ee Bee 22S 
® o2°0o > a & Bsc 
Zi A < a 
us ys eames) it rf ae Se yd se 
1872 eco)h) 24 sesh cere ee 
LST oe 2a 2S ieee ee eee ee 
1874 sou hla nesses 
1875-2]: 22) 24, Meets 35 .29 
Meh (KO) soe Biel ae a oe a Se 37 es 
1S 2e =) LO Sif 255 aa 40 ay 
1878 ___- Bi a cs Mit Bde pera 40 oh 
1879 ...-|, 22 | 185, Apr, 2 -- 40 29 Anth. Soc., Feb. 17. 
1880... 19 | 154, July 20__ 41 | Biol. Soc., Dec. 3. 
1881...) 18. | 162, dimly 182: 38 25 
1882 2...) 16 | 149, May i... 34 .23 
1883 42.4), 17 9-149, Dee 31-2 38 26 Math. Sec., Mar. 29. 
1884 _.-..| 385 | 178, Dee. 20_+ 42 .26 Chem. Soc., Jan. 31. 
1885_---| 22 | 179, Jan.16__| 47 OR 
PESGet2— |, 718 183, Dec. 18_- 47 AAG 
VSSieSe a lo aLOle Mec iale ae 49 .26 
Meaniues!” 18.6 | seen ayo 40 .265 
In a general way there has been a continuous growth of the So- 
ciety as regards membership, and the rate of growth, whether con- 
sidered as a geometric ratio or as an arithmetic increment, has 
progressively diminished. The average attendance has likewise 
increased, but its law is not evident. The ratio of attendance to 
membership has ranged in ten recorded years from .23 to .29, the 
mean being .265. 
The total active membership passed through a secondary maximum 
in 1880 and a minimum in 1882-’83. The current attendance 
exhibits a subsidiary maximum from 1877-’80 and a minimum in 
1882. The curve of accessions shows maxima in 1874, 1879, and 
1884. While there are many series of contemporaneous events 
with which these might be compared,,one only will be considered, 
namely, the formation of other scientific societies in ‘Washington 
and the formation of the Mathematical Section within our Society. 
