ON THE SEICHES OF LOCH EARN. 



365 



house built for it by Mr James Murray. Unfortunately the body of the observer 

 conceals the well cylinder, and the vertical box which encloses the counterpoise. 



To give an idea of the results obtained by the instrument, tracings (scale f) 

 of four portions of the limnograrn are given in figs. 3, 4, 5, 6. The indented time-line 

 is omitted, except in fig. 6. Near the middle of fig. 3 will be seen the time-mark 

 across the limnograrn. The absence of any break or discontinuity in the trace shows 

 that the pen returned exactly to the same point on the paper after the band had 

 been pulled. This furnishes a very important test that the apparatus was sensitive 



Fig. 2. 



and in good working order, 

 stand this test. 



Our Sarasin instruments in their original form would not 



Adaptation of the Sarasin Limnograph. 



It was found very easy and not very expensive to adapt the Sarasin limnographs 

 to the model above described. All the external gear was removed. The travelling 

 recording bar and its driving pulley were taken away, and a pair of rails fitted to carry 

 an improved form of recording waggon, which is figured in Mr Murray's paper on the 

 " Preliminary Observations on Loch Earn." # Instead of the band a piece of sounding 

 wire was used, which was passed over the two pulleys which had carried the travelling 



* Part II. of this series. 



