1904 



FORESTRY AND IRRIGATION 



439 



and open forest of an uninhabited re- 

 gion; hence no attention was paid to 

 them. Near Sims, on the line of the 

 Southern Pacific, and at various points 

 in Shasta county, troublesome fires 

 have existed. The two most serious 

 fires, and the only ones given much 

 newspaper space, occurred in the region 

 adjacent to San Francisco Bay. One 

 was in Marin county, near San Rafael, 

 and for a time threatened the Mt. Tamal- 

 pais Railway and tavern ; the other 

 burned over a large area and destroyed 

 much property in Santa Cruz county, 

 and only by strenuous effort was kept 

 from running through the state Red- 

 wood Park in the Big Basin. 



Pennsylvania The following letter from 

 and the Fair. Dr. J. T. Rothrock, until 

 recently Commissioner of 

 Forestry for Pennsylvania, explains why 

 his state made no forest exhibit at the 

 World's Fair : 



Editor Forestry and Irrigation. 



SIR : Mr. Alfred Gaskill's comments 

 on page 404 of September issue of your 

 journal are both natural and proper. 

 He writes thus : " Far more significant 

 is the failure of such leading states in 

 the forestry movement as Pennsylvania, 

 Maine, and Minnesota to show what 

 they have done to maintain and extend 

 their woodlands." It simply remains 

 for Pennsylvania to say that at the time 

 when application was made for space 

 there were but 900 square feet available 

 and we required at least 2.500 square 

 feet in which to make suitable exhibi- 

 tion of what was doing here in forestry. 

 We thought that no display at all was 

 better than an inadequate one. 



Individually, I have long believed that 

 Pennsylvania could use the money avail- 

 able for forestry purposes to better ad- 

 vantage than by taking part in these 

 constantly recurring expositions, to meet 

 the demands of which attention and 

 funds must be diverted from more pro- 

 ductive work. However, out of respect 

 to public opinion, Pennsylvania was pre- 

 pared to have made a forestry exhibit 

 if space could have been obtained. 



In what has been said there is in- 

 tended no suggestion of the unwilling- 



ness on the part of the authorities to 

 accord the room desired if it had been 



available. 



J. T. ROTHROCK. 



Studying Mr. Charles S. Slichter. 



Underground engineer, U. S. Recla- 

 Waters. mation Service, who re- 



cently conducted the 

 investigation of the underflow in the 

 Arkansas River Valley in western Kan- 

 sas, is now engaged in similar work in 

 the vicinity of El Paso, Texas. A brief 

 reconnaissance indicated that therecould 

 be no underflow of any consequence at 

 the narrows of the Rio Grande above 

 the city. At the site of the proposed 

 international dam the distance between 

 the walls of the gorge is less than 400 

 feet, and the Mexican borings seem to 

 indicate that bed rock is reached at 

 about 86 feet at deepest point. The 

 limited cross-section of less than 40,000 

 square feet could not transmit a large 

 volume of ground water, even if other 

 conditions were favorable. The highest 

 velocity ever determined for ground 

 waters is 100 feet per 24 hours. As- 

 suming this maximum velocity at the 

 above cross-section and a porosity of 

 one-third, the daily discharge would be 

 i, 333,000 cubic feet, or 15^ second feet. 

 The gradient of the water plane at the 

 narrows is but 4 feet to the mile, and 

 all other indications point to a low 

 rather than a high velocity. 



There are none of the common and 

 usual indications of an underflow at this 

 point. If a free underflow existed, a 

 perennial stream would undoubtedly ex- 

 ist in the narrow gorge above El Paso. 

 In addition to a perennial surface flow 

 through the narrowest portion of the 

 gorge, above the gorge and near its 

 converging sides the ground water 

 should have a slightly artesian char- 

 acter ; but none of these indications were 

 found to be present. 



Notwithstanding the above consider- 

 ations, work was begun to determine 

 the actual rate of underflow. In the 

 coarsest strata of sand met with in drill- 

 ing the wells the velocities were found to 

 be between 2.7 and 2. 9 feet per 24 hours. 



An important fact brought out by the 

 investigation is the increasing hardness 



