ATA: 
Office at the Board of Woods and Forests, and a Committee was 
appointed to represent to Her Majesty’s Government the expediency 
of having accurate descriptions and drawings taken, at the public 
expense, of the geological features exhibited in the cuttings and > 
excavations of railroads throughout the kingdom; these are now 
easily accessible, whilst the railways are in process of formation, 
and an accurate knowledge of them may be of great scientific as 
well as commercial importance in future times, when the sections 
now laid open are covered up. I am gratified to inform you that 
many influential members of the Institution of Civil Engineers have 
expressed a zealous desire to cooperate with us in carrying into effect 
this measure, in which they are so pre-eminently qualified to render 
most efficient assistance. 
DISSECTED GEOLOGICAL MODELS. 
A valuable communication has been lately made to us by Mr. 
Sopwith, an active Member of the Institution of Civil Engineers as 
well as of our own Society, showing, by a series of small models 
constructed of differently coloured plates of wood, the advantage of 
expressing in a solid form those fractured conditions of the strata, a 
right understanding of which is of the greatest importance, both to 
the working of coal mines and of metallic veins. Many of the com- 
plicated phzenomena of curvatures and complex intersections of plane - 
surfaces cannot be adequately represented by any kind of geome- 
trical drawings or plans; to the perfect knowledge and ceconomical 
working of a mineral district, it is essential that the subterranean 
relations of all the strata should be correctly known and expressed 
in an intelligible form :—lIst. The original order of stratification. 
2nd. The amount of dislocation by fracture. 3rd. The changes of 
the surface produced by denudation; and all these can be intelli- 
gibly and simultaneously expressed by models. 
The deceptive appearances frequently caused by faults or frac- 
tures, are represented by dissecting and making the models move- 
able in the direction of these faults, « so that the strata may be restored 
to their original: position, and again shifted or dislocated. The still 
further difficulties which arise from the denudation of the upper por- 
tions of the dislocated strata, can be adequately expressed only by 
the solid fac-simile of nature which a model affords. 
Among the subjects represented in the models prepared by Mr. 
Sopwith, are the relative position, depth, and upcast and downeast 
dykes of the component strata of the Newcastle coal-field, and the 
strata of the great carboniferous limestone series, with their nume- 
rous intersections by mineral veins, in the extensive lead-mine di- 
stricts of Alston Moor and. Crossfell. All the varied and complex 
pheenomena of these highly valuable repositories of coal and lead, 
which are continually perplexing and impeding the progress of the 
practical miner, are made perfectly intelligible, when their details 
are expressed in a dissected model. The mercantile value also of 
these mineral districts is obviously dependent, first, upon a correct 
knowledge of the amount of coal and mineral veins which they 
