534 
Proceedings of the Eoyal Society 
attention to the great additions which a complete series of electrical 
observations, made at Ben Nevis Observatory, would be likely to 
make to our knowledge of these subjects, if the experimental 
difficulties in the way could be surmounted. 
The figures given represent the deflection of the spot of light of 
the galvanometer, in scale-divisions. 
The sign 4- prefixed to a figure indicates that the current passed 
through the galvanometer down the line-wire to Fort- William. The 
opposite direction is indicated by a - sign. The sign ± indicates 
that the current was variable in direction. ± 0 indicates that the 
current was extremely faint, the spot of light oscillating about the 
zero-point. The sign oo indicates that the spot of light was driven 
off the scale altogether. Where the current was very unsteady, the 
figures are in old style type. 
September 20. — Bidge of high pressure between two cyclones, one 
lying to south-west and one to north-east. Centre of former ad- 
vancing towards Denmark in afternoon. 
21. — Decided change of wind from north-easterly to westerly at 
12 hours. Barometer rising all day, with temporary dip, accom- 
panied by southerly wind, from 18 to 20 hours. 
22. — Depression with centre well out to north-west at 8 hours, 
passed to northwards in afternoon. Anticyclone to south-east. 
Rain in morning, diminishing from 11 hours to 13 hours, when wind 
shifted slightly; heavy rain at 17 hours. Wind backing till 
18 hours, when it blew from south by west. Barometer fell till 
14 hours, steady till 17 hours, after which fall continued till 
22 hours. Temperature rising at night. 
23. — Cyclone, centre to north-west going eastwards. Anticyclone 
to south-east, moving over Italy. Wind shifted more to north at 
4 hours, and rain stopped, with temperature falling rapidly. 
Shower between 8 hours and 9 hours. Mist clearing at 10 hours — 
on again after 13 hours. A little snow, with shift of wind to 
easterly, at 16 hours. Wind changed to south-westerly, followed by 
snow, after 22 hours. 
24. — Cyclone to north-east off coast of Norway — centre travelling 
eastwards along 70th parallel N. lat. Centre of anticyclone shifted 
to south-west of Ireland since 8 hours of previous day. Snow fell 
till 8 hours and after 1 1 hours. Currents and meteorological condi- 
