84 Book of Engineering 



realise that the vast Belgian Congo is splen- 

 didly supplied with a river system which 

 is unexcelled in any similar area. Not only 

 is there the Congo River, but there are 

 numerous tributaries which make up some- 

 thing like 11,000 miles of inland water- 

 ways within the colony. 



Unfortunately, apart from rapids, a great 

 deal of this total is made up of stretches 

 of water which has an insufficient depth 

 for the steamboat or barge of the usual 

 type. Indeed, a recent series of careful 

 surveys shows that there are about 9,000 

 miles of waterways where a craft must have 

 a draught of not more than three feet; 

 another 1,800 miles will take boats drawing 

 up to six feet, whilst the remainder about 

 600 miles in all is available for ocean- 

 going craft. 



Something has been attempted and 

 successfully so far as the experiments have 

 been carried out with aircraft, particularly 

 of the seaplane and flying-boat types, but 

 it will be appreciated at once that the load 

 of such craft is negligible in comparison 



