xxxvi. Chemical Section. [February 27th, 1920. 



it is of so particular a type that it might well be required of an 

 exeeptionalh' specialized civil engineer. As applied to buildings 

 the nature of much of this knowledge is obvious, but again 

 there is much that is not so apparent. Thus, for instance, 

 knowledge as to the suitability of ground to cany the founda- 

 tions of heavy buildings is obvious, but the effect of the soil 

 upon metals which may be embedded in it or of diffused waste 

 waters which may find their way into it, is not on the surface 

 so apparently necessary as it actually is. In the construction of 

 the buildings the ordinary attention to lighting, ventilation and 

 so on is required, but consideration must also be given to the 

 material of which the building and roofs are constructed. Ferro- 

 concrete ma} r be an ideal material for warehouses and the like, 

 but in chemical plants in which the removal of vessels and pipe 

 lines is frequent, it is objectionable on account of the great 

 difficulty which it offers to such re-arrangements. 



In the arrangement plant accessibility to all parts should 

 receive first consideration. It is bad policy to bury tanks or 

 pipe lines in the ground as leakages cannot be observed, and 

 repairs are only possible after much labour and difficulty. 

 Where it is necessary to have tanks or other portions of 

 apparatus below the ground level they should be placed in a 

 well with sufficient room for a workaman to move freely round 

 them, observation then becomes possible. 



Although hard and fast lines cannot be laid down in the 

 matter, a study of the unit system of construction of plants is 

 frequently profitable. This system enables a plant to be erected 

 with the minimum cost in its erection so far as drawings, 

 patterns, etc., are concerned, and further^ if any portion of a 

 plant consisting of a number of units breaks down, the effect 

 upon the output of the whole plant is considerably less than 

 when the construction is that of one or two very large sections. 

 The adoption of standardization of construction materials would 

 greatly facilitate the employment of the unit system, and even 

 in other cases would simplify erection and extension. It would 

 be necessary, however, before adopting standards to have the 

 uses to which the materials are to be applied very carefully 

 thought out, thus, whilst it is common to use earthenware 

 drain pipes as conduits for gases in chemical works, these are 

 invariably much too heavy for the work they have to do, with 

 the result that supports are infinitely stronger than is necessary 

 and much labour is involved in erecting or renewing the pipe 

 lines. Such heavy pipes as are used in this country are rarely 

 seen in continental works where light earthenware specially 

 constructed for this purpose is employed. 

 The centralising of units of power, steam supply, etc., may be 



