890 EXPERIMENT STATION EECORD. 



It is pointed out that drainage practice in irrigated regions differs materially 

 from ordinary practice in the humid sections. Under the usual conditions in 

 irrigated fields 6 ft. is found to be about the minimum depth advisable. The 

 frequent use of a few well located and deep drains to intercept the underflow 

 before it reaches the land which requires drainage is another striking differ- 

 ence. The method of draining by relief wells, an adaptation of the Elkington 

 system of tapping underground springs, is emphasized as especially applicable 

 to the improvement of saturated irrigated lands. 



It is estimated that there are at least 800,000 acres of irrigated land which 

 now require drainage to make them profitably productive. 



Tidal marshes and their reclamation, G. M. Warren (U. 8. Dept. Agr., 

 Office Expt. Stas. Bui. 2JiO, pp. 99, ^j/s. 16, figs. 21). — This bulletin reports special 

 investigations of two reclamations in New Castle County, Del., and two in Cum- 

 berland County, N. J. These reclamations have been carefully surveyed, 

 current-meter measurements made of the sluice discharges, and the results 

 studied in considerable detail from agricultural, engineering, and economic 

 standpoints. The forepart of the report contains a definition of terms and a 

 short discussion of tides. Following detailed descriptions of the experimental 

 marshes a general summary and discussion covers the proper character, con- 

 struction, and maintenance of sluices, levees, ditches, and pumping plants, soils, 

 ground-water vegetation and its relation to the water-table, treatment of lands 

 and crops grown, and financial and sanitary aspects. There are also brought 

 out the reasons for poor progress and causes of failure in so many of the tidal 

 reclamations of the past, and the questions which should be decided before any 

 reclamation is undertaken are discussed. 



Supplemental investigations are reported of the marsh lands at Green Har- 

 bor, Mass., and others in New England, New Brunswick, and Nova Scotia. A 

 rather complete history of the first-mentioned reclamation is given in order to 

 bring out the legal aspects of the questions often involved in attempted 

 reclamations. 



In conclusion, the author explains the success of tidal reclamations on the 

 Bay of Fundy, and the apparent indifferent success which has attended many 

 of the reclamations farther south along the Atlantic Coast, as follows : " Un- 

 questionably the fundamental reason lies in the great nature-bestowed gift of a 

 large range of tide, which has built the marshes high and permits the sluices 

 to play long jDeriods of time, thus securing adequate drainage easily, cheaply, 

 and certainly. There are, of course, other reasons of historical, physical, and 

 economic nature which have contributed, but they are relatively insignificant 

 and are more than offset by our own economic needs and by American energy, 

 enterprise, and resourcefulness." 



Dynamite for preparing' land, J. T. Garrett (A'eto England Homestead, 63 

 {1911), No. 15, p. 318). — In giving his experience with the use of dynamite for 

 subsoiling for corn, the author states that rows were marked 15 ft. wide and 

 plowed out with a 1-horse turning plow. With a li in. steel bar holes were 

 made in this furrow 40 in. apart and 30 in. deep into the subsoil and through 

 hardpan, loaded with one-half of a i lb. stick of dynamite, and several holes 

 fired at one time. A yield of 120 bu. of corn per acre was obtained. An ad- 

 joining area of the same size subsoiled with a plow and mules produced 82 bu. 

 per acre. 



The author also states his experience with dynamite in growing melons. He 

 expects beneficial results from this dynamiting for at least 10 years. 



Examination and classification of rocks for road building, including the 

 physitial properties of rocks with reference to their mineral composition 

 and structure, E. C. E. Lord (V. 8. Dept. Agr., Office Put). Roads Bui. 37, pp. 

 28, pis. 10, fig. i).— This is a revision of Bulletin .31 of the Oflice of Public 



