METEOROLOGY OF 1 897. 
5 
south and the Platte on the north, and it has the character- 
istic climate of the Great Plains. Mr. J. E. Payne has been 
the Superintendent and observer. The reductions have 
been made at the home station. 
§ 7. The Arkansas Valley Experiment Station at Rocky 
P'ord, is located on the south side of the Arkansas river, 
about 50 miles east of Pueblo and 240 miles from the central 
station at Port Collins. This station is in the irrigated 
strip along the Arkansas, with uncultivated range extending 
south to the state line, and north to the Platte. The obser- 
vations during the year have been interrupted by a change 
in the management of the station. Mr. P. K. Blinn severed 
his connection with the station the first of May, and Mr. W. 
F. Crowley took up the work the first of August. Observa- 
tions have been carried on at this station since 1890, and 
most of the time continuously. The latitude of the station 
is 38° 3', and the longitude 103° 45', and the elevation above 
the sea level 4160 feet. 
DESCRIPTION OF THE INSTRUMENTS. 
§8. The standard for testing the thermometers is the 
Normal Standard Thermometer of Green, No. 5483. Be- 
sides the special care taken by Green in its manufacture, 
this was tested at the Yale Thermometric Bureau, and sub- 
sequently at the U. S. Weather Bureau The results not 
agreeing, it was afterwards sent to Professor W. A. Rogers 
of Colby University, who made a careful study of its pecul- 
iarities. All thermometers are tested at the freezing point, 
and those used for continuous observations are tested in 
comparison with 5483. 
§9. I'he maximum and minimum thermometers are 
shown in Figure i. The maximum thermometer is of the 
(Fig. 1.) 
Green pattern, in which there is a constriction in the tube 
just above the bulb. When the temperature rises, the 
mercury is forced past the constriction, but if the tempera- 
