WATER SUPPLIES FOR IRRIGATION. 



71 



irrigationist unflinchingly joins issue with 

 the opponents of the movement. If, as 

 they urge, it is impossible to meet his 

 reasonable demands because existing legis- 

 lation is adverse, or insufficient, his posi- 

 tion is that such legislation must be 

 amended, and by no means that social 

 progression be for a moment retarded 

 thereby. 



In order to render such a position ten- 

 able, it is undoubtedly necessary for the 

 irrigationist to urge far more than a pure- 



ly local or transitory issue. This he 

 squarely claims to be doing, and he esti- 

 mates his labors solely according to their 

 beneficial results upon the whole common- 

 wealth. 



It is from a study of the broader side of 

 the irrigation movement that any just ap- 

 preciation can be placed upon these; it is 

 from an unprejudiced consideration of its 

 aims by the public, and their unfalter- 

 ing prosecution by its friends, that success 

 may be expected in their attainment. 



WATER SUPPLIES FOR IRRIGATION. 



II. ORIGINAL RESEARCH RAINFALL AND STREAM DISCHARGE. 



BY F. C. FINKLE, C. E. 



NO irrigation engineer can afford to give 

 a project his unqualified endorsement 

 by basing his examinations and opinions 

 wholly on the data derived from reports 

 made by others, no matter how complete 

 and full such reports may appear. 



The most perfect human minds have 

 their failings and are liable to mistakes, 

 and reports, especially those prepared 

 under government supervision, often con- 

 tain serious errors, inaccuracies and omis- 

 sions caused by carelessness or a lack of 

 proper interest in the work. The impor- 

 tance of verifying data obtained from other 

 sources than from personal investigation 

 and research is therefore apparent. 



It is often the case that no reports, gov- 

 ernmental or otherwise, are obtainable, 

 from which any information about the 

 particular locality in question can be 

 drawn. This may be due to one of sev- 

 eral causes. The country may be new and 

 unexplored or only partially explored; the 

 data known maybe too limited or conflict- 

 ing to be considered reliable; the region 

 may heretofore have been considered of 

 too little importance to merit investigation 

 at the public expense, or some other cause, 

 known or unknown, may be responsible 

 for the existence of no reports in relation 

 thereto. 



In cases of this kind original researches 

 have to be commenced de novo and com- 

 pleted before any conclusion can be 

 reached. 



*A11 rights reserved by the author. 



We will now endeavor to discuss the 

 methods to be employed and the manner 

 in which the work should be done in order 

 that a perfectly fair, reliable and conserv- 

 ative conclusion may be arrived at. 



One of the principal things, and one 

 which requires the most careful and long 

 continued observation to determine, is the 

 rainfall on the watershed tributary to a 

 stream. For the determination of this a 

 pluviometer should be employed on as 

 many different stations on the watershed 

 as possible. 



A pluviometer is an instrument for 

 ascertaining the amount of rain which 

 falls from the clouds. It is usually made 

 of brass or some other metal not easily 

 corroded and consists of a cylindrical dish 

 with open top and a long tube connected 

 to its bottom, which is otherwise closed, 

 the tube being of such diameter as to give 

 a sectional area equal to one-tenth of the 

 top area of the dish itself. The edge at 

 the top should be very thin and the meas- 

 uring rod, for which allowance in propor- 

 tion to its thickness must be made in pro- 

 portioning the sectional areas of the dish 

 and tube, should be graduated in inches 

 and tenths of inches. This instrument, 

 when in use, should be set in level, open 

 ground with its top just above the top of 

 the grass and apart from buildings and 

 other obstructions, and the weeds and 

 grass should be kept trimmed below its 

 top. When these conditions are observed 



