440 



THE POFrL.iR SCIESl 



STHLT 



It dxMiM be not^, howrrer, that there h« been little d« 



tW CA&al fxcftvation on the I e isthmus,* tt mad 



Oiklkn briow ! i U Uhe I The work 



n..w 



~, hereafter, 

 'rogren cm 

 :: vhkh can 

 Tt>riL It m 



^u6a Hill 



abas- 

 ii 

 to 



^QS {mx has r> Uic v 



«r " "^^uirement for •« 



be iv.a.ntaineii, as DOW shov 

 bait be anfwered b^ *^ -^ -^^ 



protebk that the :_.-. 



f^f T\rv>r!v« if m oaff cred br rards of ex 



. . dams coi : rirr, from 



hifb gronad at « -^l to Sosa IlilU va.- ^' >:on foimd 



that theae atiui' tmea were ill-advi«ed. '\ e mtick and mod of the 

 « ManglaTV^ d not support the loa *( a moderate fill There 



much - ' and lateral d Laplace: 



This was in no wise fatal to 

 red the f 

 Miraflof^v vhere excavauon iur illux u 



The wx>^' the main dam, t^ .;^, has barely com- 



». ' "^ :.-^ u*m will be of eauii , ave a crest laig& of 



^Jtgj^ ' • --1 - v,..-,i^}j of > ... * ^ and down stzcan, 



0f 0, . ^"t T-ial of which the 



-,alic metiiod. 



-. and a practically 



-ited acroas tiie 



_' and slippiag d a 



of the proposed 



'iiere will be other slips imtil 



nder and particokriy near 



The dooblB 



Tb* Trmtfrial V . 



it . and safe body of earth v 



Tmlier ^f the Cbagrea at Gattir 

 rock -t was being pla. 



•tractore is of do gre^t ice. 



diq>beeneDt of lajers of yielding ma' 

 the edges of soch fills, is sufficient to 

 ftT?«"* g the feasibility of a Etructure 

 fe«r of sue- • the ur • - 



vmtcr at oou. 

 tent and permc^ar:..!} ( 

 '••rings aDd shaft' * 



11 ^ 

 daa 



/.^_-^i I ... ,,.^ 



ATS 



a mofeneDi of 

 depoaila, flie ex- 

 .^rmatioD ob t a iwfd 

 or leas ooojectinaL 

 ■■m the safety of the 

 :« resatt. 

 are f_ ■ " b«t little basia for fliem. 



71,,. , ;ry to the dam froi a moderate underflor if wit- 



Able r^ are taken to let the wter come to the surface at flie 



dc/wn-rtream toe of the dam throng' and, gravel and beofcen rock 

 • InU^rm^tUm U |mbli.i»d ia tk* Co- 4 oi Ttbraxrj 10, 1»», tfcit 



ih» Fr«>4r«t la Ortobrr, 1«HJ, autborittid « widening of t^ ^^"^''^ 

 •ItWo Ti»0f«4<mtfc« bottom toOO fe«t. Tfci* f««t ^— 



tW .r,^« WM writt«i. TV pn tm of wideaiaf with* ^ ^ 



tkt .t^r.f d*T»tfc of this MctiB of the eaaal may be apttUd to 

 , tk*T*i<fr; aomt tiam loagvr. 



^Uemlly 



I 



