326 
acquisition to every local museum ; and as a knowledge of 
science advances, there is no doubt the means of extending 
it will rapidly increase. Thus in the compass of the last 
few months an admirable adaptation of the process of electro- 
typing has been made to a geological purpose, viz., the 
obtaining cheap and perfect fac-similes of fossil remains. 
By this process, several beautiful examples of which (pro- 
duced by Mr. Jordan) were exhibited by him at the last 
meeting of the British Association, it is not too much to 
hope that local museums may be furnished at a small cost 
with accurate transcripts of the very best specimens of fossils, 
and this w^ould add fresh interest and value to the drawings 
of fossils proposed to be kept in connection with the sections 
of railway cuttings. 
Uniformity of colour is also highly desirable, but less im- 
portant than uniformity of scale. Several specimen sheets 
have been prepared, and may be had on application, as 
already described. The colours used in Mr. Greenough's 
last edition of his geological map of England and Wales, or 
in Mr. Murchison's Silurian System, will afford a good scale 
of colour to those who are possessed of these works. The 
colours used in the Ordnance Survey may be adopted, or each 
artist may employ his own judgment, provided, however, that 
in every case each sheet shall contain a written description 
of the rocks, &c. represented by each colour, and also con- 
secutive letters or fio^ures to distinofuish the colours on the 
section and reference. If this is carefully attended to, it is 
not of material consequence w^hat colours are employed, 
since in copying, at any future time, this can be easily im- 
proved upon. It is not so much for nicety of detail, that 
attention is now urged, but for those more important geome- 
trical data, w^hich can only be obtained by measuring the 
strata while they remain exposed to view, and by accurately 
delineating them on a uniform scale. 
