104 



transport chalky matter over open clayey and heavy lands. The 

 ice, too, in passing over a variety of rocks has ground them up 

 and mixed the waste together. The open claylands have been im- 

 pregnated with chalk, and a great difference in fertility is noticed 

 on the eastern side of England in the regions north and south of 

 the Thames. Some of the finest wheat lands have been produced 

 by the mixing of the soils, whilst rain, wind and frost have 

 furthered this action. 



The water supply of calcareous areas is further noted for a 

 specialised formation which gives rise to Artesian Wells. The 

 water of London is mainly derived from this source. Previously 

 the water supply for the City was taken from the Thames above 

 Staines. This is now inadequate, and London derives the greater 

 amount of its water from the chalk by Artesian Wells. The 

 fountains in Trafalgar Square were some of the earliest, if not the 

 earliest, Artesian Wells in the country. The character of water 

 from the chalk that add to its domestic use are its purity, clearness 

 and free supply of air and carbon dioxide, whilst its great draw- 

 back is its hardness, which lessens its cleansing properties and 

 increases its wastefulness in soap. 



In calcareous areas springs often gush out of ground higher 

 up the valley after heavy rains have raised the level of underground 

 water, but with light rains, or during seasons of drought, the rivers 

 dry up. This is singularly common along the Pentridge Downs 

 and Salisbury Heights. After heavy rains springs frequently issue 

 from irregular sources of this description and produce floods in 

 limited areas. The chalky regions of England are comparatively 

 waterless as regards river courses. A full map of the river basins 

 of England clearly shows the course of the chalk and limestone 

 across England by the diminution in the number of affluents to the 

 principal rivers and streams. Within these very pervious areas 

 the winter rainfall collects to form springs, whilst the summer rains 

 freely evaporate owing to the porosity of the soil. 



In this connection it is worthy of note how few rivers cross 

 the chalk. There is an almost total absence of gaps through the 

 chalk, and nearly all our railway lines leaving London have been 

 compelled to tunnel the chalk to get through. 



Incidentally chalk was the means of establishing safety on the 

 new railway line between Brockenhurst and Bournemouth. On the 

 construction of this direct communication great difficulty was 

 experienced in maintaining the gravelly cuttings and embank- 

 ments. These were constantly undermined and were incessantly 

 slipping away. Chalk was the means of saving the situation, 

 dykes were dug and filled with chalk, and has proved entirely 

 satisfactory, and the experiment has since been successfully 

 repeated in many parts of the country. 



The chalk is a present monument to Transmutation. Slowly, 

 but surely, even that portion now above sea level is being ground 

 down. Portions fall into the sea to be crushed to the finest mud 

 and carried away by ocean currents to be absorbed by present 



