[Footnote 22: The student is recommended to consult in particular, Appendix I. "On Geological Surveying" in _The Student's Manual of Geology_, by J. B. Jukes (Third Edition, Edited by A. Geikie), p. 747, and _Outlines of Field Geology_, by Sir A. Geikie (Macmillan and Co.).] The ordinary geological map is one which shows the outcrop of the strata, subdivided according to age, as they would be seen upon the surface of the earth after stripping off the superficial accumulations, and it is to be feared that the term 'geological map' is associated in the minds of most students with a map of this character and of no other. Nevertheless, a great many most important observations other than those connected with the order of succession of the strata are capable of representation upon a geological map, and the possession of a large number of maps of any area upon the geology of which a person is engaged--each map to be used for recording observations of a particular kind--will save much writing in note-books and, what is of more importance, will allow him to compare observations which have been made at different times at a glance, instead of causing him to search through a series of note-books. Still, however well furnished with maps, the geologist will find a note-book essential[23]. [Footnote 23: As a result of some experience, the writer recommends every student to acquire some skill in the use of the pencil, and if to such a degree that he can combine artistic effect with accuracy, so much the better. An acquaintance with photography is invaluable: often the possession of a camera would enable a section to be recorded, which is otherwise lost to science.]