372 



PROFESSOR CHRYSTAL AND MR JAMES MURRAY 



index limnograph, Endros # was able to carry out in little over a month a very com- 

 plete survey of the Wagingersee, involving the determination of over a dozen different 

 periods and at least seven nodal lines, an extraordinary result even for so skilled and 

 practised an observer. 



As the Sarasin instruments were useless for our purposes during the greater part of 

 the available time in August and September, and it was desirable for general reasons 

 to keep the new Waggon Recorder at St Fillans, we had to depend almost entirely on 

 the use of index limnographs for the purposes of the general survey of Earn. The final 

 form in which we used these instruments is due to Mr James Murray, and is described 

 in his paper (Part II. of this series). 



I may take the opportunity to describe very briefly two particular forms of highly 



^jU/t 



□ 



ftv^ 



t 



E 



D 



Fig. 14. 



Fig. 15. 



portable self-recording limnographs which, I think, might prove useful in seiche 

 surveying. 



The Lever Self-recording Limnograph is shown in a schematic diagram in fig. 14. 

 As originally constructed, it was a toy made by one of my children for his own amuse- 

 ment out of such materials as he could beg from acquaintances ; but an actual working 

 instrument has been sent to Jerusalem to be used in preliminary observations on the 

 Dead Sea. 



A cord or wire from the float, F, can be attached at various parts of the lever, AOP, 

 which is pivoted at 0, and has a counterpoise C, whose weight or position can be 

 varied. The recording drum, D, is driven by a cheap clock, which is screwed to the 

 bottom of the drum, and whose arbor, K, is fixed to the stand iS, which in its turn is 

 mounted on a small hand-camera tripod stand. The pen, P, works on the swing-gate 



* " Die Seiches des Wagingei-Tachingersees," von Anton Endros : Hitz. ber. d. Kyi. Bayer. Alcad. d. Wiss., Bd. 

 xxxv., 1905, p. 447. 



