FOR GREAT BRITAIN AND IRELAND. 4 



on its sides, so that a straight pier will be sufficient, of which 

 Burnt Island in the Firth of Forth is an example ? " 



" Third. Is it necessary to protect the berthage by means 

 of a curved or kanted pier, as may be seen in many places 

 where the sea is not very heavy ? " 



"Fourth. Is it necessary that a space of water should be 

 inclosed between two piers inclined to each other till they 

 nearly meet, and admitting (through the narrow entrance 

 thus formed) only a small portion of the outside wave, which 

 is afterwards reduced by expansion into the enclosed area ? 

 Examples of this may be seen at Ramsgate, and many other 

 places on the coasts of Britain." 



" Fifth. Must we have recourse to what may be called a 

 compound harbour, consisting of one harbour within another, 

 where the outside waves are first reduced by expansion into 

 the area of the outer or stilling harbour, after which a yet 

 greater reduction is attained by the second expansion of a 

 portion of the reduced wave into the area of the inner 

 basin ? Examples of such double harbours are common 

 on all such coasts as are much exposed." 



" After the engineer has satisfied himself as to the 

 general character or class of design required, which is 

 undoubtedly the principal question to be settled, he must 

 next consider the details. Where the place is much 

 exposed he must arrange the different parts of the design 

 so as .to produce a harbour which may be easily taken and 

 left in stormy weather, without endangering the tranquillity 

 of the internal area ; for it is the combination of these two 

 qualities, of easy entrance and a smooth interior^ which alone 

 constitute a good harbour. Lastly, he must fix the width 

 of the piers and height of the parapets, and assign the sizes 

 and determine the arrangement of the constituent materials 

 in such proportions as to ensure the stability of the work," 



VOL. IX. E. 4. E 



