286 Balch : [J. F. I.,

tion by foliage, the influence of the original dressing of the masonry, especially on well tooled or bush-hammered sur- faces, etc.

It is apparent, therefore, that the elements of strength, on which the coherence of the grains of stone depends, in resistance to weathering, are so varied, that with many kinds no single known method, artificial or natural, can be relied upon without question and without confirmation. We yet need to seek for light through comparison of results from all promising methods of possible application, and often to gratefully accept even an approximation to the truth.

[To be concluded.]

Slated Meeting, Wednesday, February 8, 1899.

S U B T E R R A N E A N ICE DEPOSITS IN AMERICA.*

BY EDWIN SWIFT BALCH.

The whole st~bject of subterranean ice is so bound up with questions of temperature that it seems well to say a few preliminary words about unde rg round tempera tu re s in general. Underground temperatures may best be studied under three heads: the normal, the super-normal and the sub.normal. The normal or ordinary temperatures scarcely change the whole year round. There is a superficial layer of soil or rock, of but very slight depth, which is affected by the outside temperatures ; beneath this there is usually a layer, the temperature of which is about that of the mean annual temperature of the locality; below this the temperatures increase slowly with increasing depth below, the surface. This increase may be roughly stated as about I o C. for every 32 meters in depth. Super-normal temperatures at or near the surface are very rare, and are due to special causes. Thus, there are a few caves which have temperatures much above the mean annual temperature of their locality. In such cases, the heat is generally due to the presence of hot

*~ Copyright by E. S. Baleh, 1899.

April, I 8 9 9 . ] Subterranean Ice Deposits. 287

springs or to volcanic act ion in the immedia te neighbor- hood. * Sub-normal t empera tu re s in the superficial layer are rare, b u t less so than super-uormM t e m p e r a t u r e s , These t empera tu re s m a y be abnormal ly low w i t h o u t descending to the freezing-point. Somet imes , however , they are so low as to be accompanied b y the format ion of ice.

For some years I have been col lect ing all the da ta I could find abou t sub te r r anean ice deposi ts in America . Scientific journals , one or two books of travels, and cu t t ings from local newspapers , have furn ished informat ion abou t a number of places, and cor respondence wi th persons res id ing in thei r ne ighborhood has g iven more. My notes include over fifty locali t ies ranging from Greenland to Tier ra del Fuego. Much of this informat ion comes from the repor ts of t ra ined observers , such, for instance, as the paper of L ieu tenan t Cantwell , desc r ib ing the ice cliffs on the K o w a k River. A b o u t the accuracy of mos t of the informat ion I feel bu t l i t t le doubt , except in regard to the measu remen t s given, concerning which there is a t endency to repor t th ings underground as much larger than t hey real ly are.

On the wes t coast of Greenland a n u m b e r of bur ied glaciers are repor ted . t These seem to occur when a glacier finds i ts ou t le t in the sea and for some reason s tops flowing. Then some of the Arc t ic mosses and lichens, which flourish in spi te of the cold, g radua l ly make thei r way over the ice, first in thin l~yers, la ter in thick masses, the y o u n g plants t r ampl ing down the older ones unti l t h e la t ter turn to a rich mould. The seeds of grasses and flowers find their

w a y to this unti l the whole p la teau becomes a garden of green, gold and white.

Much frozen soil is found in Alaska. Prof. Israel C. Russel l saw m a n y s t ra ta of ice in the banks of the Yukon and he says that s t ra ta over 30 meters thick have been found. Much of the Klond ike count ry is frozen down to bed rock, 8 or IO meters deep. In this case the miners are said to cut off the moss wi th a shovel, and then to bui ld

F. Kraus, Hf'hlenkunde, p. 86. t W. E. Meelaan, Philadelpkia Ledger, 1896.

288 B a l c h : [ J . F. I.,

a fire which thaws out the g r o u n d for 5 or io cent imeters . T h e y dig this out and then s tar t ano the r fire and cont inue the process. A t the o ther end of the cont inent , in Tierra del Fuego, ice and lava are said to be found inter-stratified for a g rea t depth, each winter ' s snow be ing covered by a new lava sheet . On Chimborazo also, H u m b o l d t says that enormous heaps of ice are found covered wi th sand and far be low the infer ior l imit of the pe rpe tua l snows.

In our W e s t e r n S ta tes there are several caves which retain ice, and which are of cons iderab ly larger propor t ions than any in the East ,* and there is no doub t tha t more will be d iscovered in the future . Places where ice remains, w h e t h e r caves or not, are r epor ted from Wash ing ton , Ore- gon, California, Montana / f W y o m i n g , Colorado and Ari- zona. A par t icu lar ly in te res t ing place in the S ta t e last named was b r o u g h t to m y not ice b y the d is t inguished archaeologist, Mr. F rank Hami l t on Cushing. I t is a cleft in a lava bed, which, be ing roofed at the fu r the r end, m igh t be descr ibed as a cave. In this the ice remains unt i l J u n e or July, m u c h la ter than anywhere else in the ne ighborhood . The Zuni Indians have a myst ica l feeling a b o u t this, cal l ing the ice the b rea th of the gods ; the snow they consider a sor t of down. Th e region is very arid, and wa te r ve ry precious, to wh ich fact the associa- t ion of the supe rna tu ra l wi th the occurrence of snow and ice a m o n g the Indians m a y be explained.

In the S ta tes east of the Rockies some thirty-five sub- t e r ranean ice depos i t s are k n o w n - - i n Maine, N e w Hamp-

* One of these is in Washington . ' I t is a lava cave, and is 56 kilometers from the mouth of the Whi te Sa lmon River. Described by R. W. Raymond, Overland Monthly, November 3, I869, P- 42I. Ano the r is o~n Cow Mountain, near Cripple Creek, Col.

Y Mr. Rober t Buffer, of San Jose, Cal., wrote to me tha t he had examined a glaci~re cave and a freezing well in Montana, where such wells are not un. common. The people in t he ne ighborhood t h i n k the ice forms in summer. Mr. Buffer invest igated the question of cold-air d raugh t s coming from these glaci~res. He found tha t , on rapidly walk ing into t hem on a ho t day, the same sensat ion was produced a s t hough one were s tanding still and the air were in motion. He also satisfied himself that , a s f a r a s he had observed, the ice was formed by no o ther cause t han t he na tura l cold of winter.

Jour. Frank. Inst., Vol., CLXVIZ April, 1899. (Ba&h.)

]

THE BLUFF AT DECORAH, ~OWA. LOCATION OF CAVE ABOVE

WHITE CROSS. (Photo. by Mr. A. F. Kovarik.)

April, I899 ] Subterranea~t fee DejPosits. 289

shire, Vermont , 'Massachusetts, Connecticut , New York, Pennsylvania , Virginia , Indiana, Missouri and Iowa. The most sou ther ly of these is in about 37 ° nor th la t i tude. The deposits in Arizona, which are yet fu r ther south, are at a much grea ter al t i tude.

Four of these only may properly be called caves. These are at Manchester , Vt., Ellenville, N. Y., Farrandsvil le , Pa., and Decorah, Ia. The l i t t le cave near Manches ter is in a marble format ion, and, so far as I know, it is the only marble cave in the world where abnormal ly low tempera- tures have been found. On the 5th of July, I898, there was plenty of snow in it, bu t no th ing tha t would s tr ict ly be defined as ice.

At Decorah, Ia., is a l i t t le cave or l imestone fissure on the banks of the Iowa River. I t is qui te famous because the capil lary t h e o r y - - t h a t ice migh t be formed by pressure on the water dr ipping th rough rock cracks--was formu- lated to explain i t . . On the 3oth of September, I898, there was no ice in it, and the t empera tu res were normal. Nei ther were there any t iny tubula r fissures visible, bu t ins tead of these, there were quant i t i es of fossils.*

Near Ellenville, N. Y., is a cave- -or perhaps more cor- rectly a gorge, as it is minus a roof - -which is the largest natural ref r igera tor in the Eas te rn Uni ted States. Several friends of mine have found snow and ice in it in past years in Ju ly and Augus t . Las t year, on the 9th of October, neither snow nor ice was present, and the tempera tures were only s l ight ly below tha t of the outs ide air in the shade.

In Clinton County, Pa., on the banks of the Susquehanna River, opposite to the vil lage of Farrandsvil le , is a mite of a cave.t I t can only be entered for about 2 meters, a l though there are several cracks leading fur ther into the rocks. The postmaster and the railroad agen t at Farrandsvi l le assured

*Mr. Alois F. Kovarik, of the Decorah Institute, published a valuable se- ries of observations about the Deeorah Cave, in the Scientific American Sup- plement, No. II95 , November u6, I898. He thinks that the cold of winter is thesouree of eold.

t This oould also be described as a windhole.

VOL~ CXLVII. No. 88o. 19

290 B a l c h : [J. F. L.

me tha t ice was never visible there in winter, but t ha t it was found there from April, usual ly all th ro~gh the summer months . On October I Ith, there was no ice in sight, bu t after fifteen minutes ' exposure, the t he rmomete r dropped to 6 ° C., an abnormal result, showing, in my opinion, the presence of ice fu r ther in. The rocks also were abnormal ly cold.

Of rock gorges which act as ref r igera tors I have seen three in the Eas tern Uni t ed States. One is the, so-called, Ice Glen at Stoekbridge, Mass. I was told tha t ice remained there la ter than elsewhere in the ne ighborhood, sometimes as late as May. On the 3d of J u l y there were no trace of ice or snow, a n d the t empera tu res were normal .

There is a grea t gorge near Randolph, N. H., nor th of the Pres ident ia l Range , be tween Crescent and Black Mountains. Th i s is called the Ice Gulch. The sides are qui te sheer in m a n y places, and the bo t tom is choked wi th an accumulat ion of boulders. A m o n g these there was a small quan t i t y of ice in one or two places on the i l t h of A u g u s t last. This ice was unusua l in formation, ne i ther solid nor prismatic, but full of air bubbles. I t c rumbled away in small pieces under the teeth.

In the Pres ident ia l R a n g e i tself is the great King ' s Ra- vine, on Moun t Adams. The bo t tom is covered wi th huge boulders, and among these, some years ago at the end of September, there was p len ty of pr ismat ic ice.

There are a number of rock taluses in the Appalachians, where ice is found. One of these is on Lower Ausable Pond, in the Adirondacks, at the nor th base of Mount Sd- bille or Colvin. I t is a huge ta lus of grea t Lau ren t i an ~?) boulders, among which are numerous hollows, which might by cour tesy be called caves. On the i2 th of July, Mr. E. I. H. Howell went wi th me to th is spot, and in three hol- lows we found ice, in two of these places in considerable. quant i t ies . Mr. Howell has been repeatedly at this spot dur ing past summers and always found ice, so it mus t be considered a perennial glaci~re.

Two days later, on the indicat ions of Mr. Otis, the chief guide of the Adi rondack Reserve, I explored the south talus

• of the Giant of the Valley. In two places about i kilometer

April, 1899. ] Subterranean Ice Deposits. 29I

apart, and in each case in hollows among the boulders there was p len ty of ice. I did not follow the ta lus t h roughou t its whole extent , as the walk ing was fearful ly bad, bu t appar- ent ly ice m i g h t be expected anywhere, as I found it at once at both 'p laces I inspected. One mass was cer ta inly 5 or 6 meters long by 2 in wid th and I in depth. The ice was very pure, hard and non-prismatic. In one of the hollows, where there was only a l i t t le ice, the t he rmomete r regis tered 6 ° C. after fifteerl minutes ' exposure, about I meter from the outside, and about t mete r from the same spot in the shade of a tree, it reg is te red 26 ° C., a difference of zo ° C. wi th in less than 2 meters.

Near R u m n e y , N. H., is a boulder ta lus where Mr. John Ritchie, Jr., Secre tary of the Appa lach ian Mounta in Club, of Boston, some years ago found ice in Augus t . The Sheriff of R u m n e y accompanied me to this place, and said tha t ice was genera l ly a b u n d a n t there in summer. On the xSth of Augus t we found none and the tempera tures normal.

A t Wate r town , N. ¥. , under the tracks of the New York Central Rai lroad, are some rock cracks, in f ront of which cellars have been built , and these are used to store beer barrels. On the Iz th of September there was no ice in the cracks, and the lessor of the cellars told me it had all mel ted away early this summer, on account of the great heat. Near W a t e r t o w n is the picnic g round of Glen Park, where there is a hollow or rock basi~a, where ice and snow some- times lie over unt i l July. There are cracks in the rock sides of this hollow, in which ~ce remains over near the mouth , but it is not found any dis tance within.

An hour on foot to the nor th of the Pennsy lvan ia Rail- road Sta t ion of Spruce Creek, H u n t i n g d o n County, Pa., at the base of the Tussey Mountain, is a grea t talus of broken (sandstone ?) rock. I t is some 150 meters long and 3o meters high. At the base of this ta lus are some small pits which are said to have been dug by farmers and which act as na tura l ice-houses. In these pits, on the 5th of October last, I could see my brea th dist inct ly, and on the talus the air was much colder than anywhere around it. I t h o u g h t I saw ice far in among the rocks, bu t I could not be sure. There mus t surely

292 Balc/t : [J. F. I.,

have b e e n some, however , for the t e m p e r a t u r e was abnor- mal ly cold.

Freez ing wells are a form of na tura l re f r igera tor not un- common in the Eas te rn U n i t e d States. One of these was said to be at Owego, N . V . I v is i ted the place on the 23d of last June , and found tha t the well had existed, bu t that i t had been blocked up m a n y years ago. Mr. Pres ton, who had l ived bes ide the well all his life, in formed me tha t he had more than once been down in it, tha t it passed first through a layer of sand, then th rough a layer of gravel, and tha t he h ad seen the sides covered wi th ice, and tha t ice had some- t imes filled it solid abou t half-way up.

A t Brandon, Vt., is ano ther freezing well. This has been descr ibed in the Geology of Vermont as conta in ing ice as late as ju ly . The owner of t he well assured me that i t froze solid every winter . I was there on the 7th of July, and twice lowered a the rmomete r , and each t ime, after ten minutes , i t regis tered only I3 ° C., a s t r ic t ly normal tem- pera ture .

A t Decorah, Ia., also, there is a well which is repor ted as f reezing up every winter . A t the end of S e p t e m b e r there was no ice in it.

I wish now to make a br ief r6sum6 of the chief points which these ice deposi ts , and a cer tain n u m b e r which I saw in Europe in 1897, have s u g g e s t e d to me, since I del ivered a lec ture on " I ce C a v e s " before the Frankl in Ins t i t u t e two years ago. ~

Na tu ra l re f r igera tors fall under some th ing like five main heads :

(I) Gull ies and t roughs where ice remains. (2) Boulder ta luses conta in ing ice. (3) Ice shee ts overla id b y soil or rocks. (4) Wells , mines and tunnels which freeze at t imes. (5) Caves wi th abnormal ly low t empe ra t u r e s and most ly

conta in ing ice. For four of these five different rock format ions , as far as

they are connec ted with ice, we have only two te rms in

~Journal of the Franklin Institute (I897), 14.a, 161-178.

April, I899. ] Subterranean Ice Deposits. 293

English and those the ent i re ly incorrect ones of " i ce cave" and " i ce gorge," and the more I have followed up the sub- ject, the more do those names seem misnomers t o m e . We say " l i m e s t o n e cave" or " l a v a cave" and in the s a m e w a y we should say " i ce c a v e " when the sides and roof of a cave are formed of ice; tha t is, we should reserve the te rm for the hollows at the ends of glaciers whence the glacier waters make their exit. Curiously enough, the Germans use the same inaccurate phraseology as ourselves, and there is only one term which is really generic, namely, the French glacikre naturelle. This is comprehensive and accurate, embrac ing the geological s t ruc ture and sugges t ing the mode of forma- tion of the ice. In my opinion we should ei ther adopt the French glacikre or use its Engl ish equivalent , " n a t u r a l refrigerator."

The next point I wish to touch on, relates to the mode of formation of the ice of these glaci~res. In every case glac- i~res seem to me to be purely refr igerators, which preserve the supplies of ice and snow stored in them dur ing the winter. T h e y all follow the same general laws as to their origin, modified only in s l ight degree, according to the vary- ing na tura l condit ions of the place, such as the water-supply, or the protect ion from sun or wind, or the th ickness of the overhead rocks, or the a l t i tude o.r la t i tude. I cannot see that there is a n y t h i n g very remarkable about the fact tha t the cold of win te r is able to penet ra te and make i tself felt sometimes for a very s l ight depth' in the earth 's crust, a depth so far as yet known never exceeding i5o meters. And it seems to me. tha t glaci~res only emphasize a law of na tu re which has doubtless been formula ted many times in connection with springs and phreat ic waters, and that is, t ha t where we find very cold waters u n d e r g r o u n d , we may be sure tha t they have pene t ra ted from the outside.

The excessively hot summer of i898 has furn ished some valuable proofs of the fact tha t the cold of win te r is the originator of the ice, and the hea t of summer its destroyer. . At Rumney , for instance, where there is genera l ly ice in August, there was none last year. A t Ellenville, I was told there was always ice in the cave. Yet I found none, and

294 B a l c h : [J. F. I.,

the t empera tu re was normal, and as far as I could learn this was someth ing never known before.

The fact tha t there was no ice las t s u m m e r at the freez- ing wells of Brandon or Decorah, is a proof tha t natura l ref r igera tors have no th ing to do wi th a glacia lper iod. This poin t was se t t led abou t caves long ago, b u t i t m igh t have been c la imed to hold abou t f reezing wells, as we cannot be sure how long a t ime the gravel beds they are dug in had been frozen. But f reezing wells ev iden t ly do not depar t mater ia l ly in thei r act ions f rom other glaei~res, since there was no ice at the f reezing wel l s of Brandon or Decorah las t summer , and the t e s t imony shows conclus ively that t h e r e was p len ty of it las t win te r and tha t there will be p len ty this winter . A n y l inger ing doub t s I may have had abou t the cat3illary t h e o r y - - t h a t is, of the ice fo rming by p r e s s u r e n h a v e been dispel led by v is i t ing the cave at Deco- rah, where there were none of the supposed hai r fissures, and which is not especial ly different f rom similar caves in Europe• If, as is somet imes claimed, the ice is fo rmed by evapora t ion or b y expans ion of the air, and tha t these factors are mos t ac t iye when the wea the r is hot tes t , then the pas t s u m m e r afforded the bes t poss ib le condi t ions for their demons t ra t ion , and there should have been ice at Ellenvil le and Decorah .

T h e s u b j e c t of evapora t ion is closely connec ted wi th a ve ry impor t an t poin t a b o u t glaciates, and tha t is subter- ranean d raugh t s and the m o v e m e n t s of air. Believing, as I do, tha t it is the cold air o f win te r which causes the ice, i t is necessary to consider i ts action• First , there is a form of sub te r ranean hollow, where there are at least two open- ings, of which one is h igher than the other. In these there are a lmost a lways d raugh t s whose direct ion varies ac- cording to the outs ide tempera ture . W h e n the air wi thin is colder than tha t of the air outside, then b y its own we igh t the air wi th in the cave flows o u t a t the lower opening. When , on the contrary, the air wi th in is warmer than the a i r outside, then this w a r m e r ins ide air r ises and leaves the cave at the upper opening, and is, of course, replaced b y an equal vo lume of cold outs ide air f lowing in at the

April, I899.]' Sub te r ranean Ice Deposits . 295

lower opening. Th i s is the p h e n o m e n o n of b lowing caves or windholes , and when ice is found in them, i t is a lways at t h e lower end, as i t is a t t ha t end t ha t the cold air enters, and i t is also to tha t end tlaat wa te r g rav i ta tes . In- s tead of the ice in these windholes be ing fo rmed by evapo- rat ion, it seems to me t ha t when the air flows out at the lower end, it m u s t t hen have a t endency to vapor ize the ice and car ry it away as mois ture .

T h e n the re is a class of caves w h e r e there is only one en t rance and where the body of the cave is lower than the entrance. In these the air in s u m m e r is appa ren t ly stag- nant, and hence t hey have been ca l l ed ' s t a t i c caves. T h e name is not descr ip t ive , however , for in cold wea the r the heavy win te r air sinks i n t o these caves and displaces the air within, of course se t t ing up some motion. Even in s u m m e r I ques t ion w h e t h e r the air is a lways as s t agnan t a s it seems. A t the Glac i&e de Saint-Georges , in the Swiss Jura, there is the en t r ance to the cave, and at one end of the cave there is an open ing in the roof. In Augus t , 1897; the air seemed per fec t ly still wi th in the cave on the ice floor, ye t s t and ing n~arly u n d e r the hole in the roof, I found tha t the smoke of m y c igar rose ve ry rap id ly s t r a igh t up ; it seemed a lmost to be drawn or sucked up f rom above, and cer ta in ly t he air was no t s t a g n a n t at t ha t spot. Th e re can be no quest ion, it seems to me, t ha t it is the m o v e m e n t of the heavy cold air of win te r downward into these caves which supplies the cold which forms the ice in them.

A l t h o u g h I disbel ieve tha t the evapora t ion in windholes is ever s t rong enough to cause ice to form, ye t I have no doub t wha teve r , t ha t in caves wi th a t e m p e r a t u r e some degrees above freezing-point , when there is e i ther r u n n i n g water or s t rong drips, evapora t ion m a y be, and some- t imes u n d o u b t e d l y is, a fac tor in lower ing the t e m p e r a t u r e somewhat ; ~ and as in some windholes there is somet imes mois ture on the rock surfaces where the air cu r r en t passes,

This is also the opinion of M. E. A. Martel. Les .dbimes, Paris, 1894 , p. 564, and M#moires de la Soci~t# de Sp~l#ologie, 1897.

296 Balch. I J. ~. I.,

the evaporat ion from these surfaces doubt less sometimes lowers the t empera tu re of the air currents appreciably.*

There is, however, no reason to th ink tha t evaporation ever lowers the t empera tu re of air currents below freezing- point. Tak ing all the facts which I have myself observed, and all t ha t I have read in the reports of others, m y con- clusion is tha t we have absolute ly no proof t ha t under- g round evaporat ion is ever effective in produc ing ice.

A good deal of confusion has been occasioned by the nomencla ture of these caves. One kind has been termed windrMtren, or windholes or b lowing caves; the other, eis- hMzlen, or ice caves or s tat ic caves. The impor t an t point, however, in this connect ion is tha t somet imes ice occurs in both these classes of caves and somet imes it does not. I wish to repeat t ha t the only ra t ional t e rmino logy is the French one, to speak of any place where there is ice under- g round as a glaci~re or refr igerator . If there are two open- ings at different al t i tudes, a n d hence dis t inct draughts , then we have a. windhole or b lowing cave, qui te independent of whe the r there is or is not any ice.

Ano the r scarcely not iced point about na tu ra l refrige- rators is their relat ion to life. Apropos of this is the fol- lowing s t a t emen t about the talus a t Ausab le Pond. This is direct ly on the shores of the lake, and it is known among the Adi rondack guides tha t in f ront of the talus is the best spot in the whole lake to catch trout . Of course this is because the water of the lake is coldest at tha t spot, and t rout always seek the coldest water. Iia the l i te ra ture about glaci~res, however, I have found reference to an insect, stenopltylax hieroglyplticus,t This has been found in three eaves s i tua ted a long dis tance apar t in the French Alps. A1- t hough this single ease can scarcely be considored as estab- l i sh ing a special glaciate fauna, ye t the subject is worth fu r the r invest igat ion.

*Further observation on this point will be necessary. The cave at Farrandsville and the talus at Spruce Creek seem to me to offer unusually good opportunities for study.

t G. F. Browne, lce Caves in France and Swilzerland, London, Long- mans, I865 ; aud the same in Good Words, Edinburgh, November, I866.

your. Frank. Inst., Vol. CLXV[L April, z899. (t~alch.)

GORGE AT ELLENVILLE, N . Y . (Photo. by Mr. Davis.)

April, x899. ] Problem of the MississippL 297

There is more to be said in regard to p lant life than to animal life. My gu ide to the Rando lph Ice Gulch told me that he had been a s su red tha t Alpine p lants s imilar to those found on Mounts W a s h i n g t o n and A d a m s were found in tke Gulch, b u t tha t t hey were not found on the ne ighbor ing Crescent and Bald Mountains . On the talus at Spruce Creek, it s eemed to me tha t the flora was s o m e w h a t dif- ferent f rom tha t immed ia t e ly su r round ing it. Whi l e at the talus a t Ausab l e Pond, Mr. Howel l called m y a t ten t ion to the flowers of the b u n c h b e r r y ~nd also to oxalis, a p re t ty white flower. These were in full bloom, a l though t h e y - were at leas t two weeks la ter than they Were on the sur- rounding mounta ins . Here , therefore, is a case where the cold air coming from the rock crevices affects the flora in the vic ini ty sufficiently to re tard its deve lopment .

T H E P R O B L E M O F T H E M I S S I S S I P P I .

BY HEgMAN HAUPT, C. E., Washington, D. C.

In May, I897 , the wri ter pub l i shed several art icles in the New York Sun on the Mississippi R i v e r problem, the aim of which was to show that of the sys tems proposed, ne i ther the levee, the outlet , the reservoir, nor any other, singly, would secure pro tec t ion from overflow, bu t tha t a combina t ion of several and an in te l l igent appl icat ion of certain recognized principles, wi th a careful s t udy of local condi t ions was essential to a pract ical solut ion of the p rob lem presented.

Since tha t t ime an exceedingly va luab le paper has been given to the publ ic by Mr. Wi l l i am Starling, Chief Eng ineer of the Lower Yazoo Dis t r ic t in Mississippi, g iv ing detai ls not in possess ion of the wr i te r at the t ime of the publica- tion of the art icle referred to.

There has been much cont roversy as to the effect of levees in caus ing e levat ion of the beds of s t reams and very posi t ive asser t ions have been made on bo th sides.

The s t a t emen t was made by Prony tha t " the Po and the