Dr. J. W. Evans — Presidential Address. 511 



the Survey publications. Such a belief can hardly be very -wide- 

 spread, for, as a matter of fact, comparatively few of the general 

 public realize tbe value of tbe work of the Geological Survey, and 

 still fewer make use of its publications. Municipal libraries, other 

 than those of our largest provincial centres, are rarely provided with 

 the official maps and memoirs relating to the surrounding areas, and 

 in the absence of any demand the local booksellers do not stock 

 them. This cannot be attributed to the cost, for though most of the 

 older maps are hand-coloured and therefore expensive, the later 

 maps — at least those on the smaller scales — are remarkably cheap, 

 and the memoirs are also issued at low prices. 



The true explanation appears to be that a geological map conveys 

 very little information to the average man of fair education who has 

 received no geological instruction. This is certainly not the fault of 

 the Survey maps, which compare very favourably with those of 

 other countries, and have been greatly improved in recent years. 

 In particular, the introduction of a longitudinal section on each map 

 and the substitution of the vertical section drawn to scale for the old 

 colour index must greatly assist those into whose hands it comes in 

 obtaining a correct view of the succession of the strata and the 

 structure of the country. Some of the maps are, it is true, so 

 crowded with information — topographical and geological — that it is 

 frequently difficult, even for the trained geologist, to read them 

 without a lens. This is largely due to the fact that they are printed 

 over the ordinary topographical maps in which there is a great 

 amount of detail that is not required in geological maps. In India 

 the Trigonometrical Survey are always ready to supply, as a basis 

 for special maps, copies of their own maps printed off plates from 

 which a portion of the topographical features have been erased. 



The best remedy, however, would be to extend the publication of 

 the maps on a scale of 6 inches to a mile. For many years all 

 geological survey work has been, in the first place, carried out on 

 maps of this scale, but they have not been published except in coal- 

 mining areas. There the geological boundaries are printed, but the 

 colouring is added by hand, which makes the maps comparatively 

 expensive. In other localities manuscript copies of the geological 

 lines and colouring on the Ordnance Survey maps can be obtained at 

 the cost of production, Avhich is necessarily considerable. There is, 

 I believe, a wide sphere of usefulness for cheap colour-printed 

 6 inch geological maps, especially in the case of agricultural and 

 building land, for which the 6 inch Ordnance maps are already in 

 demand. They afford ample room for geological information, and, 

 accompanied by longitudinal sections on the same scale without 

 vertical exaggeration, their significance would be more readily 

 apprehended than that of maps on a smaller scale. It may be noted 

 that this is the favourite scale employed by those engaged in 

 independent geological research for their field work, and, when the 

 area is not too great, for the publication of their results. 



It would be of great advantage if there were a uniform usage by 

 which the position in the stratigraphical series of rock outcrops 

 were indicated by colour and their lithological character by stippling 



