June 19, 1889.] 



Garden and Forest. 



289 



GARDEN AND FOREST. 



PUBLISHED WEEKLY BY 



THE GARDEN AND FOREST PUBLISHING CO. 



Officr : Tribune Building, New York. 



Conducted 



by . . . 





Professo 



rC. 



S. Sargent. 



ENTERED AS 



SECOND-CLASS MATTER AT THE POST OFFICE AT NEW YORK, N. Y. 



NEW 



YORK, 



WEDNESDAY, 



JUNE 



19. 



1889. 



TABLE OF CONTENTS. 



PAGE. 



Editorial Articles : — The Danger from Mountain Reservoirs. — Tlie Australian 



Acacias 289 



Tlie Artof Gardening — An Historical Sketch. VL — Persia, 



Mrs. Schuyler Van Rensselaer. 290 



Recent Botanical Discoveries in China. IV W. B. Hemsley. 291 



New or Little Known Plants : — Synnga Japonica (with figures) C. S. S. 291 



Entomological: — The Imported Elm-leaf Beetle Professor y. B. Smith. 292 



Cultural Department: — The Late Garden ]V. N. Bull. 2g2 



Strawben-ies • W. F. Massey. 293 



Lselia purpurata John Weathers. 294 



Papaver Caucasicum. — Alstromerias O. 294 



Sweet Peas M. B. Faxon. 294 



Dwarf Pears Professor L. H. Bailey. 294 



Notes from the Arnold Arboretum f. 295 



The Forest : — Forest Interests in Pennsylvania. I J. B. Harrison. 297 



Recent Publications 297 



Periodical Literature 298 



Correspondence : — West American Oalcs Charles Harvard Shinn. 298 



Chinese Magnolias near Baltimore IF. F. Massey. 298 



Motto on a Sun-dial F. L. M. 298 



The United States Nurseries S. 299 



Recent Plant Portraits 299 



Notes 300 



Illu.strations : — Syringa Japonica in the-Arnold Arboretum, Fig. 114 293 



Syringa Japonica, Fig. 115 295 



The Danger from Mountain Reservoirs. 



ON the very day when the city of Johnstown was anni- 

 hilated and the prosperous Conemaugh Valley was 

 transformed into a scene of desolation and death, which 

 has never had a parallel in the history of the country, a 

 dispatch was prepared in Washington for the Associated 

 Press to the effect that Secretary Noble had approved of 

 the plan for continuing the survey of the arid lands pro- 

 posed by Major Powell, Director of the Geological Survey. 

 This plan looks to the construction of a system of reser- 

 voirs in the mountain regions, where the waters are to be 

 stored for use upon the dry plains below. The project 

 contemplates operations of greater magnitude and imiDort- 

 ance than any which our hydraulic engineers have yet 

 attempted, and many features of the proposed work de- 

 mand more careful study than they seem to have received. 

 The one point, however, which the Pennsylvania deluge 

 forces upon our consideration is the threat of destruction 

 which hangs over a valley when a vast amount of water is 

 imprisoned above it. There are barriers which avail 

 against the sweep of a tornado ; no conflagration is so 

 swift and fierce but that a hopeful fight can be organized 

 to quell it ; but there is absolutely no escape from a flood of 

 water like that which raged through the Conemaugh Valley. 

 ■When we consider the thousands of square miles which 

 it is proposed to irrigate, and estimate the vast amount of 

 water that will be needed to give each acre as much as 

 might fall elsewhere upon this space in a single summer 

 shower, we can begin to understand what an enormous 

 capacity these reservoirs must have to be of any practical 

 benefit to agriculture. We are not prepared to deny that it 

 is within the limit of engineering skill to construct dams 

 that will not yield under the pressure of a given weight of 

 water. But it is a fact that both in this country and in 

 Europe the walls of reservoirs which have been pro- 

 nounced safe by experts have opened to release torrents 

 which have desolated a thousand homes. No one can tell 

 what agencies of disintegration are at work in the founda- 

 tions of such a structure. The engineer can measure the 

 pressure of so many feet of water, and if he knows the 



quality of every solid yard of material in his embankment 

 he can estimate its power of resistance when his work is 

 finished. But he never can be sure that some chemical 

 agent is not corroding an obscure portion of his masonry, 

 or that some insignificant animal is not undermining it. 

 The work of government contractors has not always 

 proved the staunchest, and when we consider the difficulty 

 of making any adequate inspection of such enormous 

 dams as those proposed for the mountain gorges of the 

 West, we must believe that there is no security for the lives 

 or property of the people who would venture to make their 

 homes below them. 



What we have said applies to the conditions of ordinary 

 times and average seasons, but besides this there is the con- 

 stant menace of some unusual danger. It is the opinion 

 of Major Powell, we believe, that all the forests should be 

 cut away from the mountains where the great western 

 rivers take their rise, so that the water will not soak into 

 the ground, but run away on the surface to be caught by 

 his dams. Another benefit to be derived from making the 

 mountains bare would be, according to this theory, that 

 the snows would all blow into the caiions, where they 

 would remain and find their way to his reservoirs later. It 

 is conceivable, however, that a warm rain or a warm wind 

 through those gorges might deliver the melted snow with 

 great rapidity. The Ardeche is a small mountain stream 

 in France, and yet the sudden melting of the snows in the 

 deep valleys at its sources so swelled its current that it once 

 delivered 1,305,000,000 cubic yards of water into the Rhone 

 in three days. For this short period it flowed with a vol- 

 ume like the Nile, and what reservoir could be trusted to 

 restrain an outpouring of this sort.? An earthquake so 

 moderate that it would do no other damage might easily 

 make a fissure in the dam of some storage reservoir which 

 would admit enough water to open a passage for the sea 

 that was crowding behind it. In short, there is danger 

 always from large bodies of water held in by artificial con- 

 struction, and the Congress of the United States should 

 exercise the utmost caution in appropriating money to 

 build such reservoirs of death. 



Of course it is easier to persuade Congress that great 

 public works like these dams will be more efficacious to 

 restrain the waters of the mountains and deliver them 

 when they are needed than is Nature's way of clothing the 

 upper slopes of the river basins with forests. Where mil- 

 lions of money are to be spent in any gigantic scheme 

 there will be hundreds of eloquent advocates to urge its 

 necessity. But perhaps the ruin in the Conemaugh Valley 

 may be allowed to offer one plea for the lives which will 

 be put in daily peril if the project is not arrested. This 

 is but one of the arguments against this scheme, and we 

 are glad to learn that Mr. Fernow, Chief of the Forestry 

 Department, is preparing a report for the Senate Commit- 

 tee on Irrigation, which will discuss the matter from other 

 points of view. It is high time that some organized effort 

 was made to check a movement which has been gathering 

 force from the plausible statement of half-truths, until the 

 government seems committed to the construction of enor- 

 mously expensive works, which all experience has shown 

 to be inadequate for the purpose they are intended to ac- 

 complish, and fraught with serious danger to the lives and 

 property of thousands. 



M. Naudin has recently contributed to the Revue des 

 Sciences Naliirelles AppUquees an instructi\'e paper upon 

 the Australian Acacias, whose bark is valuable for tanning, 

 and upon the advantages which may be expected from the 

 general cultivation of these plants in Algeria. The three 

 species which he considers the most valuable for Algeria 

 7\x& Acacia pycnaiilha, A. dectirrens and .-I. dealbata. 

 l^'.The actual amount of tan-bark of good quality in Cali- 

 fornia is not large. The Oak which supplies it {Q. densi- 

 flora) was never a very abundant tree, although widely and 

 very generally scattered in some parts of the state, and the 

 growth of the tanning industry on the Pacific Coast has 



