14 PRESIDENT'S ADDRESS. 



shallow they are apt to dry up ; if the water is deeper, its 

 depth is maintained. A rain gauge in the hollow of the 

 pond produced about a third more rain than on the open down, 

 but I doubt if any conclusion can be drawn from this as to 

 the amount of rainfall, as the wind in an exposed place would 

 blow some of the rain out of the gauge as fast as it was 

 deposited. In the Peak of Derbyshire there are quantities 

 of such ponds, or " meres " as they are called, but they are 

 always assisted with arrangements for drawing the surface 

 \vater into them, when possible, which suggests that the}- 

 are the better for a little help. In connection with this 

 subject, artificial dewponds are advertised, consisting of 

 one shallow metal tray inverted within another in which it 

 is claimed that a continual supply of water is deposited. 

 Dr. March has had for years a glass aquarium in his garden at 

 Portesham with a cover raised a short distance above it, and 

 lie tells me that this simple apparatus is always full of water, 

 which is, I believe, deposited on the inside of the cover and 

 falls into the vessel below. 



ELECTRICITY. 



The Post-office has recently completed arrangements 

 by which it takes over the whole of the Marconi system of 

 wireless telegraphy in this country with all improvements 

 which may be made during 14 years, so that in future it will 

 be worked in connection with the inland postal telegraph 

 service. The selective power of this form of telegraphy has 

 been improved, so that messages can be sent from a station to 

 another particular station without reaching others, by so- 

 called tuning. The transmission of photographs by elec- 

 tricity has much developed and is now used commercially 

 for news purposes. Electricity is also used on a few farms 

 practically in agriculture, and increases the yield 30 or even 

 more per cent. The method is to suspend a network of 

 galvanised wire about 18ft. above the ground and keep it 

 charged with electricity for about eight or ten hours a day 



