LAKE SHISHA NAG, LIDAR VALLEY
Now it is found that the axes of the great mountain ranges are also composed of granite, and it seems probable that special elevating forces have been at work to raise certain parts of their ranges above the general level of the whole. And when once such elevation has been brought about, the disparity between the higher peaks and the intervening less elevated area would undoubtedly be intensified by the destructive forces at work, for the mantle of snow and ice, while slowly carrying on its work of abrasion, would serve as a protection for the peaks against the disintegrating forces of the atmosphere, while the lower unprotected areas would be more rapidly eroded.
So argues Mr. Hayden, who further demonstrates that when, during the development of the Himalayas as a mighty mountain range vast masses of granite welled up from below, forcing their way through and lifting up the pre-existing rocks superimposed upon them, it is probable that, owing to dissimilarity of composition and to structural weaknesses in certain portions of the earth's crust, movement was more intense at some points than at others, and that the granite was raised into more or less dome-like masses standing above the general level of the growing range, and subsequently carved by the process of erosion into clusters of peaks.
The great peaks being thus of intrusive origin, the question naturally arises whether they are still being intruded upward; whether those great forces at work beneath the surface of the earth are still impelling them upward; and if so, whether they are being forced upward more rapidly than the atmospheric forces are wearing down their summits. From the geological standpoint Mr. Hayden says that it is not at present possible to say whether the elevatory movement is still in progress, but he adds that many phenomena observable in the Himalayas lead us to infer that local elevation has until quite recently been operative, and the numerous earthquakes still occurring with such frequency and violence forcibly remind us that the Himalayas have by no means reached a period of even comparative rest. The surveyor can as yet give us no more certain answer. Colonel Burrard says the original observations of the great peaks made between 1850 and 1860 were not sufficiently prolonged at any one station to enable us to rely with certainty on the values of the height then obtained. When a slow variation in height has to be determined it is better to carry out a long series of observations from one station only, rather than to take a number of observations from different stations, as is necessary and as was done in determining the absolute height of peaks. But in 1905 the Survey of India commenced a series of observations from one station, and it is proposed to observe the heights of several peaks for some years and at different seasons in each year. Then if a reliable series of results be once obtained, a similar set of observations can be repeated at a subsequent date, and any actual change of height that has occurred in the interval may be discovered.
DISTANT VIEW OF NANGA PARBAT FROM THE KAMRI PASS
Until these observations are made we cannot say for certain whether the great peaks are still rising.
The Mountain Ranges