TRANSACTIONS OF SECTION A. 483 
the sign of the variations of magnetic declination changes on passing from one 
side to the other of the ‘belt of polar light,’ that is, of the belt of maximum 
frequency of displays of the aurora borealis. He regards this fact as proving that 
the aurora is caused by vertical (or nearly vertical) electric discharges in the 
atmosphere above the belt of auroras, In connection with this he mentions that 
during the Finnish International Polar Expedition to Sodankyla and Kultala, 
real auroral beams, showing in the spectroscope the characteristic auroral line 
X= 5569, were produced on mountain-tops in Finnish Lapland ‘by means of a 
simple point apparatus conducted to the earth.’ On not fewer than sixteen occasions 
the same ray was observed in all directions when there was no visible aurora, and 
it was found that the air itself radiated the light producing this ray. 
The author goes on to state that during several expeditions to the Polar 
regions he had observed the rich development of vegetation during the short 
summer, an observation which had also been made by others. In consequence of 
experiments made subsequently, he was led to attribute this luxuriance of 
vegetation to the electric air-currents prevalent in the auroral belt. The experi- 
ments referred to were performed by means of a network of wire furnished with 
points and supported on insulating poles above the ground. This was connected 
with the positive pole of a modified form of Wimshurst electrical machine, the 
negative pole of which was connected with the earth. The author finds that the 
electric air-currents brought about in this way will produce, if duly applied, such 
effects as the following :— 
1, An increased growth of all plants, amounting in an ordinary good field to 
about 40 per cent. 
2. A change in the chemical composition of grain and roots resulting in an 
augmentation of the protein and albumenoid matter in rye of about 20 per 
cent., in barley of about 12 oe cent., and of about 9 per cent. in oats, and causing 
an increase in the amount of sugar in sugar-beets of from_13 to 18 per cent. 
The author has no doubt that similar changes would take place in all sorts of 
plants under the like conditions, and he commends the matter (further details of 
which he has given in a small book entitled ‘ Electricity in Agriculture and Horti- 
culture,’ published by the ‘ Electrician ’ Publishing Company, London, 1904) to the 
attention of those who may have the opportunity of experimenting further 
upon it, 
12. The Rainfall of the Midland and Eastern Counties of England. 
By Joun Hopkinson, Vice-Pres. R.Met.Soc., Assoc.Inst.C.L£. 
This paper concludes the series on the rainfall of the English counties, and 
contains an account of the rainfall of Shropshire, Stafford, Warwick, Leicester 
and Rutland, Northampton, Huntingdon, Bedford, Cambridge, Norfolk, and 
Suffolk. These counties comprise an area of 10,626 square miles, which is rather 
more than one-fifth that of England, and between one-eleventh and one-twelfth 
that of the British Isles. The mean monthly rainfall for the ten years 1881 to 
1890 at 52 stations in these counties has been computed, and the mean annual 
rainfall at 106 stations, being one to the nearest 100 square miles in each county. 
Rutland is included with Leicester on account of its small area, 149 square miles; 
and of the ten stations allotted to the two counties, Leicester, with 806 square 
miles, has eight, and Rutland two. Norfolk is much the largest of these counties, 
having an area of 2,026 square miles, its annual rainfall, therefore, being computed 
from the records of 20 stations. 
The annual means at the 106 stations are:—Shropshire (13 stations), 
30°36 inches ; Stafford (12 stations), 28-98 inches; Warwick (8 stations), 26-64, 
inches ; Leicester and Rutland (10 stations), 26°62 inches; Northampton (10 sta- 
tions, 25°81 inches; Huntingdon (4 stations), 23°39 inches; Bedford (5 stations), 
22'59 inches; Cambridge (8 stations), 22:90 inches; Norfolk (20 stations), 
25:44 inches; and Suffolk (15 stations), 24:76 inches; the mean rainfall for the 
whole area being 26:29 inches. 
During the ten years 1881 to 1890 the rainfall in this part of England was 
112 
