PROGRESS AT PANAMA. 451 



face unbroken, and with the vegetation undisturbed." Again, " The 

 effect of the move of the soil was very curious ; at one point the bot- 

 tom of the deflection cut had risen 3 metres where the greasy clay 

 had forced itself underneath, and at another I saw a surveying picket 

 which had moved oid of line 2^ metres, where there was no break in 

 the top soil." To my mind, the deep cut of the Culebra is the great 

 problem of the enterprise ; already its side threatens to bar the way. 



Leaving this puzzle to the contractors, and looking toward Panama, 

 the first third of the last division descends gradually to 4 metres 

 level at Pedro Miguel ; the middle portion forms a plane from 5 to 

 8 feet above the sea, and over the last 6 kilometres flow the waters 

 of the Pacific to an average depth of 5 metres, and reaching the maxi- 

 mum as Naos is approached. 



At Colon the highest tides do not exceed 58 centimetres, or 23 

 inches, while at Panama high tides reach 4 metres, or 13 feet, and 

 spring tides even G metres, or 20 feet. That vessels may pass at all 

 stages of tide, the depth of the canal from Naos to the present cross- 

 ing of the Rio Grande beyond Corozal — 9*4 kilometres — will be 9 

 metres at lowest ebb. 



The company has consulted the French Academy of Sciences con- 

 cerning the probable effect of this difference of tide-level on the canal, 

 and has been told that a lock or tidal gate will not be needed. The 

 director-general does not oppose this view, but thinks that an answer 

 to this question at present must be based on theory — that, as excava- 

 tions progress, the effect must be watched ; and that upon the knowl- 

 edge obtained the decision must rest. Plans for a tidal gate have been 

 prepared, and, if needed, it will be placed at the Boca, near Panama. 



The line of the canal is crossed twenty-eight times by the Chagres 

 between Gamboa and Colon, and thirteen times by the Rio Grande 

 between Culebra and Panama. To avoid the dangers of current and 

 overflow that would exist if these streams entered the canal, deflec- 

 tions are excavated to carry them to the sea in beds on each side of 

 the canal. The deflections of the Upper Chagres will drain the Gam- 

 boa basin and the water-shed north of the canal, and w'ill discharge 

 their waters into the Boca Grande, east of Colon ; those of the Lower 

 Chagres will transport to the present mouth of the Chagres, the tribu- 

 taries now entering the river on its left bank, the most important of 

 which are the Obispo, the Arena, and the Trinidad. The Rio Grande 

 will be deflected entirely to the right of the canal, and will enter the 

 sea at La Boca. The total length of the deflections will be 64 kilo- 

 metres. Some of them will be 40 metres wide and 3 deep ; others, 

 30 metres wide and 5 deep. Erosion will increase these dimensions. 

 Lying in valleys where feasible, the soil is alluvial, and easily exca- 

 vated. It has occasionally happened that a subterranean stream has 

 undermined the banks, and caused a break. The engineers claim that 

 so far the repairs are effective, and I see no cause to disagree with them. 



