rEBRUAET 16, 1917] 



SCIENCE 



165 



spent October 22, 23, and November 1-4, 1915, 

 in tbe Canal Zone and tbe intervening' time, 

 October 24^31, in Costa Eica. During the 

 period heavy downpours of rain were frequent 

 in botli Panama and Costa Rica and land- 

 slides were especially active. Numerous land- 

 slides were observed in Costa Eica. While 

 there, also, opportunity was ailorded in the 

 Aguacate gold mines to observe the great 

 depth to which oxidation and rock decomposi- 

 tion extends in a region where the climatic 

 conditions are similar to those prevailing in 

 Panama. 



On returning to Panama a landslide was 

 seen along the line of the Panama Eailroad 

 which interfered with traf&c for a short time. 

 The forenoon and early part of the afternoon 

 of November 2 were spent in going over the 

 entire area then in movement on both sides of 

 the Gaillard Cut and also a trip across the 

 Cucaracha slide and entirely around Gold Hill. 

 The area affected by the slides is 0.88 mile in 

 length along the canal and extends back 1,400 

 feet on the east side of the canal and 1,200 feet 

 on the west, a large part of which was then in 

 actual movement. In the afternoon, through 

 the courtesy of the Canal Commission officials, 

 some time was spent in the examination of 

 unpublished cross sections of the cut made 

 during the process of steam-shovel excavation. 



The information obtained seemed sufficient 

 on which to base an opinion and forced the 

 conclusion upon the writer that the slide 

 conditions were more serious than commonly 

 supposed and influenced him in giving expres- 

 sion to his views. Subsequent movements 

 seemed to prove that the seriousness of the 

 situation had not been generally appreciated. 



In the governor's report it is stated that 

 " probably the greatest injury done the Canal 

 was through Benjamin Le Eoy Miller, Ph.D., 

 who occupies the chair of geology in Lehigh 

 University." The writer can not accept such 

 responsibility and believes that the "greatest 

 injury done the Canal " has been the frequent 

 disappointments to the shipping public, due 

 in part to the closing of the canal and the 

 uncertainty regarding its use, but in a large 

 measure to the over-optimistic reports ema- 



nating from the Canal Zone that the slides 

 would shortly cease and permanent service be 

 established by the clearing of the channel. 

 It should be recalled that the canal was closed 

 to traffic for over 4J months after the writer's 

 conclusions were published, although the 

 shipping public was led to believe that service 

 would be re-established and maintained with 

 comparatively little delay. As stated in the 

 governor's report the canal was closed 232 

 days, between the date of opening, August 15, 

 1914, and June 18, 1916, slightly more than 

 one third the time. These facts undoubtedly 

 furnish other and more weighty reasons for 

 the shipping public's loss of confidence in 

 the present usefulness of the canal than the 

 expression of opinion of a visiting geologist. 



The writer agrees with Dr. J. C. Branner, 

 president emeritus of Stanford University, 

 who was a member of the Committee of the 

 National Academy of Sciences that went to 

 Panama last December at the request of Presi- 

 dent Wilson to study the slides and prepare a 

 report upon them, in statements which he 

 made in Sunset, the Pacific Monthly, for June, 

 1916. He says: 



But wlien one sees the sliding area extending 

 further and further away from the Canal, the vol- 

 ume of the moving masses gradually getting bigger 

 and bigger, and the very hills themselves toppling 

 over and adding to the confusion trees, mud, rocks 

 and great blocks of basalt as big as houses, and 

 when he sees that these millions of tons, that have 

 to be removed, cost about sixty cents a cubic 

 yard, he feels that some way ought to be found to 

 make the hiUs stay where they are. 



How shall the hills be made to " stay where 

 they are " is the question ? Dr. Branner as the 

 result of " forty years of study of landslides 

 in tropical countries " believes that this can 

 only be effected by preventing the heavy rain- 

 fall of the region from entering the ground 

 adjacent to the canal. It is somewhat ques- 

 tionable whether this can be accomplished and, 

 if not, there seems no alternative but the 

 complete removal of the threatening hills. 

 Perhaps some unnecessary material might be 

 removed but this would be fully compensated 

 for by the increased confidence in the canal. 

 One writer states: 



