The observations which were made in Loch Earn during August 1911 and described in the Trans. Roy. Soc. Edin., vol. xlviii, p. 629, demonstrated that in that loch there was during autumn a fairly definite temperature or density discontinuity, and suggested that the loch was a peculiarly suitable one in which to observe in greater detail the boundary waves occurring at the discontinuity. The previous investigation had for its main purpose the demonstration of the existence of standing oscillations at the discontinuity, and in that was entirely successful. The observations showed, however, that in addition to the primary standing oscillations there were other less regular movements about which the observations gave little information, as they were not made at sufficiently close intervals of time.