METEOROLOGY. 95 
The ratio of rainfall to evaporation can not be exactly determined, as 
data for evaporation are meager or wholly lacking. It has been deemed 
worth while, nevertheless, to get an approximate notion of this ratio by 
estimating the evaporation and dividing by the normal rainfall. In 
the following table this has been done and the results appear in the last 
column, headed Ratio. This table also shows the maximum and mini- 
mum annual precipitation at each station during the observation period. 
shown in column 2. 














Annual precipitation. Annual 
Place. ————_ ee Ratio. 
No. of ation. 
years. Max. Min, Mean. (estim.) 
Ins. Ins. Ins. Ins. 
hf ee ee 24 18.30 222 9.23 80 8.7 
Sent IS PP OLOSL. . 0.0 ness ed eae eS 10.41 : 
Chihtiabiia... sc... ccc ee PD ine rae 10.86 : coon 
Pree wineate. 21... sree 39 25.00 6.37 14.00 80 Ly 
got ee 26 5.86 0.60 2.84 100 2a 
RIN aes sharers ve kn © 18 12.83 32.77 7.06 go 12.7 
NTs vx spends + 0 60 0 3 25 19.37 5.26 11.74* go yey 
Es ov ve ee > wnaes 26 21.38 2.20 4-97 95 19.1 
Eigwthorne............4. 14 Sa35 1.89 4.50 80 17.5 
WY RDURITITICCA Ss 5). wic's ss ae « 22 Tragt 4.89 8.51 80 9.6 
OOTP. oo we ee ee ces 13 9.81 3.55 6.46T go 13.9 
Pee UCHICSNe, . 05. ... >. 15 1.4% 4.36 6.49 75 21.6 
ROME V IMC. once cs see 6 30s 's 6 11.64 7.49 Q.or 70 7.8 
PRIBOURIVET. 0.02 es ee oo 7 11.86 6.22 8.47 70 8.3 
OT aes ee 31.42 5-56 9.81 70 7% 
0 Ve. Sa ae ee gy ares ee 16.97 100 6.0 
*From 15 years’ observation. {From 22 years’ observation. 
Discussion.—The foregoing meteorological data are given concerning 
localities which very clearly lie within the true desert regions of North 
America. It would be impossible to outline the included areas upon a 
map except by means of data obtained by an accurate and extended 
hydrographic and biological survey. The rate of evaporation for the 
several localities mentioned is roughly estimated from data taken from 
the Report on the Climate of Arizona by Greely and Glassford in 1891. 
It is probable that actual measurements might show a variation of 15 
per cent by way of error in these estimates, the evaporation being over- 
estimated, but the ratios found may be regarded as fairly approximate 
for the regions in which the several stations arelocated. Itis to beseen 
that the evaporation at Tucson, Arizona, and at Laramie, Wyoming, 
