^{page 364 note *} The apparent anomaly may have been due to capillary action on the zinc float. In the fixed limnographs of Forel and Plantamour, the float was surrounded by a band of cloth, so as to be constantly wetted by the water. In my instrument as used on Loch Earn, this precaution was not taken.

^{page 364 note †} Red would have been much better for subsequent photographic reproduction of the limnograms.

^{page 365 note *} Part II. of this series.

^{page 367 note *} If preferred, a steel band could be used, by turning the rims of the two pulleys flat.

^{page 372 note *} “Die Seiches des Waginger-Tachingersees,” von Anton Endrös: Sitt. ber. d. Kgl. Bayer. Akad. d. Wiss., Bd. xxxv., 1905, p. 447Google Scholar.

^{page 373 note *} These were established by observations with the statolimnograph, and will be discussed in a later paper of this series.

^{page 375 note *} Phil. Trans. Roy. Soc. Lond., 1883.

^{page 375 note †} It should be noticed that this is not the critical velocity (u _c=13000v/d) at which turbulent motion begins. The critical velocity u _c at which the resistance begins to be proportional to (velocity)ⁿ, where n is a number varying from, say, 1·72 to 2·00, is again different, viz., u _c=1·325u _c.

^{page 379 note *} Or even when there is a small regular seiche giving a smooth limnogram.

^{page 385 note *} Points of symmetry, of course, if such are available.

^{page 386 note *} It was mounted on friction wheels, and magnified the seiche about four and a half times. Time-scale of limnogram, ·2 inch per minute.