ioo IMPROVED FISHERY HARBOUR ACCOMMODA TION 



added after the pontoon and foundation had firmly bedded 

 themselves. 



The advantage of putting in a foundation in this manner 

 would be very great, as the whole being continuous, would 

 probably escape that piecemeal overthrow which has 

 happened to so many sea-works, both in construction and 

 after completion. 



In the upper facing of such foundations, embrasure-like 

 notches or troughs might be left, into which the super- 

 structure of concrete would mould itself, which would give 

 the whole additional stability. 



Such a plan, Mr. Stevenson observes, merits notice and 

 might perhaps be found economical and suitable in some 

 situations, but the great difficulty is to fit the bottom of the 

 pontoon to the irregularities of the ground on which it is to 

 rest, and it is possible this has prevented the execution of 

 this method. 



Mr. Stevenson does not mention any other engineer as 

 having suggested this method of putting in low-water 

 foundations, except Mr. Bremner, of Wick, deceased ; but 

 the writer cannot but think it has suggested itself to others 

 in the profession. 



MR. RENDEL'S METHOD OF DEPOSITING PIERRES 

 PERDUES. 



The gantry and waggon method of working with tumble- 

 stone is thus referred to by Mr. Stevenson : The late 

 Mr. Rendel introduced an improved and valuable method 

 of depositing the pierres perdues or rubble used in the 

 construction of large breakwaters ; this method he first 

 employed at Millbay Pier, Plymouth, in 1838, in a depth 

 of 38 feet, and afterwards on a still larger scale, in the 



