454 EXPERIMENT STATION RECORD. 



different chapters are tlie atino.splicn', iiistniiiH'iits, ])ressurc of the air, temperature, 

 winds, evaporation and luunidity, ^(jndi'nsation and ])rei-ii)itation, optical and elec- 

 trical phenomena of the atmosphere, atmo.spheri(- disturbances, local storms, weather 

 maps, climate, and how to foretell weatlicr changi-s hj' the use of the barometer and 

 local atmosi)heri<' conditions. 



Weather conditions, \X. Elliott {lijd. Dept. Ayr. Northwest Territories, 1902, pp. 

 5-21). — Tlu' general weather conditions of the Northwest Territories are described 

 and tables are given which include data for rainfall at a large number of i)laces dur- 

 ing 1902 and previous years, temperature observations during 1902, and the relation 

 between daily temperature, total precipitation, and crop yields for different districts 

 from 1S98-1902. 



Heport of tlie meteorolog-ical ■work of the Ploti Agricultural Experiment 

 Station, J\I. Svolinsky [Rap. An. Sta. Expt. Ayron. I'loti/, S {1902}, pp. 1-23, charts 

 3). — Observations on temperature of the air and soil, atmospheric pressure, humidity, 

 jirecipitation, evaporation, cloudiness, sunshine, solar radiation, wind movement, 

 and miscellaneous phenomena are recorded. 



WATER SOILS. 



Colorado irrigation ^w•aters and their changes, W. P. Headpen ( Colorado Sta. 

 Bui. S2, p]>. 77). — This bulletin discusses the source, character, and conditions 

 affecting the nature of the irrigation waters of Colorado, especially as typified in the 

 waters derived from tlie Cache la Poudre River. Analyses of the waters of this 

 stream at different points in its course, of the stored water of the stream, and of the 

 ground water, drainage, and return seepage resulting from the use of the water in 

 irrigation, are reported and discussed in detail. Analyses of the waters of a few 

 other Colorado streams are also reported for comparative purposes, and a brief 

 account is given of a study of the suspended matter carried by the Cache la Poudre 

 in times of high water. 



The results show that the character of the water of the Cache la Poudre, and of 

 the mountain streams of Colorado in general, changes rapidly as soon as they enter 

 the plains section of their courses. The amount of total solids in Cache la Poudre 

 water was found to increase from 2.9 gr. per imperial gallon as tlie river leaves the 

 mountains to 10.2 gr. as delivered to the town of Fort Collins less than 8 miles away. 

 From the results of laboratory experiments and from the occurrence of strontium 

 and lithium in the Cache la Poudre water the conclusion is drawn that the mineral 

 matter held in solution by the streams in their mountain courses is due i)rincipally 

 to the solvent action of water containing carbon dioxid on feldspar. "The amount of 

 mineral matter which the Poudre carries through its canyon daily, assuming a flow 

 of 300 second-feet, is nearly 26 tons." This is only aljout one-half as much as was 

 brought into solution by laboratory experiments with line-ground feldspar and car- 

 bonated water, viz, 4.536 gr. x»er gallon. 



"The effect of storage is to increase the mineral matter held in solution. Some of 

 the increase is derived from the ditches through which the water flows and from 

 seepage directly into the reservoirs. A small increase, 0.5 gr. per gallon, is due to 

 evaporati(jn, but by far the largest increase is shown in instances where seepage 

 water is either intentionally stored or flows into the reservoir." The mineral matter 

 held in solution by stored water varies considerably with different reservoirs, and 

 also differs from that of the streams from which it is derived. "The salts predomi- 

 nating in the water of the Poudre while it is a mountain stream are the carbonates, 

 with some chlorids and sulphates, but as stored in Terry Lake and Windsor reservoir 

 the carbonates have almost disappeared and tlieir place has been taken by the 

 sulphates. The amounts of calcium, magnesium, and sodium sulphates which 



