ON THE SEICHES OF LOCH EARN. 



479 



total duration about half an hour. It came from E. 56° N. with a velocity of propaga- 

 tion of 19 (mile/hour), the velocity along the lake being about 30. 



As will be seen from fig. 9, the effect was to increase the total range of the seiche 

 from about 18 mm. to 50 mm., and to generate a strong BT-dicrote. It is worthy of 

 remark that the rise in the wind follows about an hour after the barometric disturbance. 

 To the spiky anemogram which then follows corresponds a strongly embroidered seiche, 



LOCH EARN Sr.FiUANS f.q.05" 



Ardrrosl^n 



Microparograph 



STatoscope, ARDrnos-TAH yqoS~ 



j-3 cm 



8 K I0 



which shows no increase in maximum range. I have tried, but unsuccessfully, to 

 find a period in the anemogram corresponding to that of the seiche-embroidery, 

 viz. T= l-5 m to l-6 m . 



On 8th September, between 16 h and I7 h , a well-marked barometric disturbance, 

 having a range of 3 mm. to 4 mm. (Aq.), caused a change of phase in the previously 

 existing UB-seiche, and also a considerable increase of range. This UB then persisted 

 for nearly 24 h , until about 13 h 15 m on the 9th September its configuration was utterly 

 destroyed by the great barometric disturbance shown in fig. 10. This disturbance 



TEANS. ROY, SOC. EDIN., VOL. XLVI. PART III. (NO. 20). 73 



