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XXII. — The Temperature Seiche. Part I. Temperature Observations in the Madiisee, 

 Pomerania. Part II. Hydrodynamical Theory of Temperature Oscillations in 

 Lakes. Part III. Calculation of the Period of the Temperature Seiche in the 

 Madiisee. By E. M. Wedderburn, W.S. Part IV. Experimental Verification 

 of the Hydrodynamical Theory of Temperature Seiches. By E. M. Wedderburn, 

 W.S., and A. M. Williams, M.A., B.Sc. (With One Plate.) 



(MS. received November 19, 1910. Read December 5, 1910. Issued separately January 21, 1911.) 



PART I. 

 Observations in the Madusee. 



§ 1. A short description of some temperature observations in the Madiisee has 

 been published in the Scottish Geographical Magazine for December 1910, and this 

 communication aims at giving a more complete description of the observations with a 

 first attempt at the mathematical discussion of oscillations at the surface of separation 

 of two liquids in a basin of varying depth and cross-section. 



§ 2. The article published in the Geographical Magazine narrates that the origin 

 of the observations was a desire on the part of the author to convince Professor 

 Halbfass, formerly of Neuhaldensleben, and now of Jena, that the theory of temperature 

 oscillations propounded by members of the Scottish Lake Survey * was of universal 

 application, and was not limited to Scottish lakes. Halbfass t was of opinion that 

 the peculiar character of our lakes — the deep valleys m which they are usually situated 

 and their steep shores — made it dangerous and unwarrantable to generalise from our 

 observations. At the same time an attack was made on our theory by Professor 

 E. A. Birge,J Wisconsin, U.S.A., who thought that the oscillations observed in Loch 

 Ness might quite well be explained by reference to meteorological conditions. 

 Observations made by Dr Exner § in the Wolfgangsee had shown the existence of a 

 temperature seiche there, but the evidence afforded by these observations was not 

 altogether convincing to Professor Halbfass. The author therefore suggested to him 

 that a joint expedition should be made in July or August to a lake of his choosing, 

 and observations made according to the methods used by the Scottish Lake Survey. 



§ 3. Professor Halbfass at once fell in with this suggestion, and his choice of a 

 lake was the Madusee, || in Hinter Pommern. This lake has a maximum depth of 



* Trans. R.S.E., xlv. (ii.), p. 420. Report on the Scientific Results of the Scottish Lake Survey, vol. i. p. 125, 

 Challenger Office, Edinburgh, 1910. 



t "Zur Frage der Temperaturseiches," Pet. Geogr. Mitt., 1909, Heft 12. 



I "On the Evidence for Temperature Seiches," Trans. Wise Acad. Sciences, Arts, and Letters, xvi. (ii.), 1005. 



§ Sitzber. der K. Akad. d. JViss. in Wien, math.-nat. Kl., cvii., Abt. ii«, Jan. and Dec. 1908. 



I| The following is a note of literature dealing with the physics of the Madusee: — Halbfass, "Beitrage zur 

 Kenntnis der Pommerschen Seen," Pet. Geogr. Mitt, 1901, Erganzungsheft No. 136. "Stehende Seespiegelsch- 

 wankungen (Seiches) im Madusee in Pommern," Zeitschr. fur Gewasserkunde, v. 15, vi. 65 (1902). Samter, "Der 

 Madusee," Archivfur Naturgeschichte, 71 Jahrg., Bd. i., Heft 3, 1905. (This includes an excellent chart of the lake.) 

 TRANS. ROY. SOC. EDIN., VOL. XLVII. PART IV. (NO. 22). 93 



