95 



upheaval of the land, and M. Bravais has, by a new method of proof, 

 arrived at the same conclusion. 



Passing about a year in the environs of Hammerfert, he observed 

 that terraces of gravel in some spots, and marks of erosion on the 

 face of the cliffs at others, indicated at least two ancient lines of 

 sea-level, which extended from the coast far into the interior along 

 the sides of the sea-loch of Alten fiord. Availing himself of the 

 water-mark left by the line of sea-weeds {Fucus vesiculosus), and 

 estimating from that horizon an approximate mean level of the tide, 

 he instituted a series of exact measurements of the altitude of both 

 the lower and upper sea beaches, or ancient water-marks upon the 

 rocks, at six different stations between the mouth of the fiord and 

 its southern extremity, a distance of ten to eighteen leagues, and; 

 he arrived at the striking result, that the two terraces of Alten fiord, 

 which at first sight, or seen only to a limited extent, seemed to be 

 horizontal and parallel, are, when measured rigorously, found to rise 

 from the levels of 46 and 92 feet (English) above the sea near the 

 mouth of the firth to the heights of 90 feet and 22 feet at its further 

 or inland extremity ! In referring you to the Memoir for the inge- 

 nious and accurate methods employed by the author to obtain these 

 results, and of which M. de Beaumont has given a very clear account, 

 I will here simply direct your attention to some of the chief geolo- 

 gical considerations with which they are involved. 



As these lines of deposit rise towards the interior, so as to mark 

 that they coincide nearly with the chief axis of elevation of the 

 Norwegian chain, and as there is a want of parallelism in the two 

 beaches, the relative altitudes of which vary much in short distances, 

 so is it obviously impossible to account for the phsenomena by any 

 former condition of the tides ; and the hypothesis of salt water lakes 

 is, from the same causes, equally inadmissible. 



Submarine currents dependent upon violent elevation of the chain 

 will, the author contends, no better explain the phsenomena, because 

 the torrential debacles which would have accompanied such move- 

 ments would have left confusedly assembled drifts, and not regularly 

 arranged terraces. It therefore seems fair to admit that these are 

 truly ancient sea-beaches. The measurements of M. Bravais show, 

 in fact, that in proceeding from the coast into the interior these beds 

 not only rise to higher levels, but that their elevation has been irre- 

 gular, viz. that whilst the sea-war<:l inclination of the older or higher 

 of the two terraces, taken from a station at the middle of the fiord, 

 is very moderate, the rise of the same beds from that central point 

 to the southern extremity of the fiord is at a greater angle, and 

 therefore, that there has not only been a much more intense move- 

 ment of elevation over one portion of this area than another, but 

 that this notable change of dip indicates the greatest movements 

 at the two extremities, the centre varying slightly from the hori^ 

 zontal. Now from these facts (independent of all the geological 

 evidence) it is argued, as before observed, that no change of level of 

 the sea will account for such an outline. 



I will pass over those parts of the report which are connected 



