884 PROCEEDINGS OF SECTION J. 



above mentioned. In fact I hojje to be able to show that the 

 advantages derivable from it are so considerable that it may 

 be looked upon as indispensable for all cities and large towns 

 of the present day. 



Taking, first, its connection with sewerage and water supply 

 woi'ks. After the genei'al principles of a scheme are decided 

 on it is necesssary to knoAV the position of all features both 

 natural and artificial before the details can be prepared and 

 worked out ; tiie trend of the ground, areas of the different 

 watersheds, position of natural watercourses, &c. must be 

 ascertained to a nicety. The actual areas occupied and the 

 character and extent of the occupation must be known, as 

 well as the material of all buildings, together with their exact 

 position, not only for the most convenient placing of the main 

 and subsidiary sewers, but also subsequently for the reticulation. 

 For laying down the main drains and water mains the lines 

 of streets and lanes with the kerbing and buildings immediately 

 abutting thereon must be accurately fixed, as well as the 

 interior details in any sections where tunnels might with 

 advantage be cut through instead of following the road. If 

 carried out in a systematic and comprehensive manner the 

 whole of the details can be fixed at what is comparatively a 

 small cost in addition to that necessary for laying down the 

 main works. When the detail survey is carried out on one 

 system of coordinates and the levels are taken in connection 

 with it, the whole of the data are ready to the hand of the 

 engineer for carrying out his part of the work. 



All land situated within cities and towns is more or less of 

 a valuable character, and as it is essential that surveys of 

 such land be carried out in a scientific and accurate manner, 

 it is obvious that it w^ould be an immense advantage if the 

 Department upon which the duties of dealing with the 

 registration of titles and land transfers devolve were in pos- 

 session of really accurate plans and records. The detail 

 survey supplies the exact position of all holdings, surveyed to 

 the one meridian, measured with the same unit of length, 

 and all referable to the same origin of coordinates, with but 

 a trifling expansion of the work which is necessary for the 

 primary object of the survey. As very nearly all the work 

 necessary to render a survey for sewerage available for land 

 registration and transfers is confined to computing and 

 plotting, the extra cost is by no means excessive, and would 

 be saved over and over again in the avoidance of disputes 

 jind litigation as to positions of boundaries, &c., the detail 



