74 KELLEY. [May 12, 1856. 



of hydraulics, being consequences of the law that, cceteris paribus, the velo- 

 city and the discharge of any river vary as the square root of the rate of fall. 



3. The third question admitted of a favourable answer. There were many 

 familiar instances in this country where the tide had been admitted by new 

 works into large areas, with great advantages to navigation, and without injury 

 to other interests. No better example existed than that of Peterborough and 

 Wisbech, at which latter place the tidal flow had been increased from 8 to 18 

 feet by the works of the Messrs. Eennie, and without affecting the flow at 

 Peterborough, some 18 miles higher up the same river ; and works were now 

 being carried out there, which might probably increase the flow at Peterbo- 

 rough (now about 6 inches at spring tides) to 3 feet, with every advantage to 

 navigation. 



A familiar and grand example of Mr. Kelley's scheme occurs in the Hooghly 

 or Calcutta river, which branches from the main body of the Ganges at about 

 170 miles above that city, and carries down large floods with a slope some- 

 what analogous to that proposed by Mr. Kelley, while the tide is felt for 

 about half of its entire length from the Bay of Bengal, under circumstances 

 well known to be highly favourable to the development of the tidal wave, 

 and somewhat similar to the case of the Severn. 



There were, however, most important engineering questions touching the 

 especial manner of leading away the new line of navigation from the natural 

 river, which could only be decided by the most careful surveys, and would 

 depend on the amount and rise of flood waters ; and the nature of the soil and 

 valley at the position considered as being best adapted to meet the various 

 contingencies of so important an engineering and geographical problem as 

 the formation of an interoceanic ship canal. 



It was a subject of infinite interest and value, and the very want of data, on 

 which to speak more precisely, was the strongest argument for its claiming 

 the attention of the Governments to its investigation by thoroughly experi- 

 enced engineers and surveyors. 



He thought it highly probable that at the junction of the Truando corrective 

 engineering works would be necessary to control the flow from the Atrato, 

 and to prevent the new cut being made a channel for flood waters ; and how 

 to do this effectually and economically was the great problem ; all others were 

 mere questions of money, and prudent adaptation of the works to the nature 

 of the difliculties to be surmounted. 



Sir Eoderick Murchison repeated, that Mr. Kelley*s object in coming 

 before geographers was to obtain their aid in bringing about a grand survey 

 of the physical features and altitudes of the whole region in question, through 

 the co-operation of the Governments of England, France, and the United 

 States, an object which he thought must meet with the support of every 

 geographer. 



The Secretary then read a paper by Captain Lort Stokes, r.n., f.r.g.s., 

 on Steam-Packet Routes between England, Australia, and the Cape 

 of Good Hope. An animated discussion followed the reading of this 

 paper, which was adjourned to the next Meeting. An account of the 

 paper and of the discussion upon it will appear in the ensuing number 

 of the Proceedings. 



