Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/205

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Throughout this space the cliffs present a series of highly interesting and instructive sections, which indeed leave us little to desire in elucidating the structure of this important district, since they traverse and expose in succession all its constituent formations from the mica slate to the floetz trap.

In endeavouring to lay before the Society a transcript from these records of nature, the general principle adopted has been that of a combined series of elevations, projected upon vertical planes of which the direction is continually shifting so as to be always parallel to the greater flexures of the coast: but, since it appeared in many instances that the introduction of perspective would convey a clearer idea of the phenomena to be represented, the principle above laid down has often been departed from; and the delineations in their present state cannot be considered either as elevations or perspective views, in any strict sense. Two principles which cannot in truth be combined have certainly thus been forced together, but it is hoped usefully so with reference to the information to be conveyed.

To those who consider the varying aspects assumed by the same points when viewed under different angles in sailing past them, it must be obvious that much of incorrectness will of necessity intrude into the attempt of persons not practically experienced