Extract

The general aspect of the coast-line at North Berwick towards the east is very well known, and has been surveyed and described on several occasions. The main constituent of the cliffs, scars, and rocky foreshore is a green ash. This ash varies greatly in appearance in different localities, certain parts being characterised by the great number of embedded blocks of rock both large and small, while considerable stretches of the ash, though not devoid of embedded fragments, contain them in far smaller numbers. It may also be observed that wherever the included blocks are found in any quantity, that there the ash becomes coarser in quality, resembling a true volcanic agglomerate. This is particularly the case at a locality named the Yellow Man. In the autumn of last year I visited the Yellow Man and was so struck with the general appearance of the place that I felt certain that here at least a volcanic vent existed, but had not time to make a close inspection. Early in the spring of this year a fresh examination was made of the Yellow Man, with the intent of finding, if possible: (1) whether a distinct margin could be assigned to the supposed vent; (2) if the rocks surrounding that vent showed the usual dipping in of the strata towards the margin; (3) if the material within the vent differed greatly from that outside; and (4) to determine the nature of the igneous and other blocks embedded in the agglomerate. When the place