TRANSACTIONS OF SECTION 6. 499 



purposes had been adopted, but that a considerable increase of durability is 

 anticipated from the chemical and molecular constitution of the metals selected. 



The other matter is the fact that a very large order for steel rails for America 

 has been taken by a house of the highest eminence in this country at the price of 

 41. per ton delivered at the works — a price which is almost astounding to those 

 who have lived long enough to remember the high price at which anj r quality of 

 steel coidd be produced in former years, and when a knife with real steel blades 

 was a prize valued because not always attained in the days of our childhood. 



It seems to me that these two facts amply illustrate the position taken up at 

 the beginning of this address, as indicating the scientific energy and mechanical 

 enterprise brought to bear upon the production of steel — in the one case by the 

 lessening of its cost, and in the other by a most important extension of its 

 application. 



The following Papers were read : — 



1. Temperature of Town Water Supplies. 

 By Baldwin Latham, C.E., M.Inst.G.E., F.O.S., F.M.8, fyc. 



The author, in this paper, drew attention to the fact that the temperature of 

 the water-supply of a town, as furnished by public waterworks, was totally inde- 

 pendent of the temperature of the water at its source of supply, and that invariably 

 the temperature of water was the temperature of the ground at any season of the 

 year at the depth at which the distributing mains were laid. The average tem- 

 peratures throughout the year, whatever the source or mode of supply, varied very 

 little, but there was great difference in the range of temperature, and that while 

 the temperature in the chalk wells at Croydon gave an average monthly range, 

 based upon daily observations, of 064°, the same water, when supplied direct from 

 the mains, gave an average monthly range of 21 - 14°, or when stored in a cistern a 

 range of 28'05° ; while water supplied from the Thames in Westminster gave an 

 average monthly range of 24"69°, but the average yearly difference of temperature 

 between the chalk water supplied at Croydon and the Thames water supplied in 

 Westminster was only 0'67°. 



2. On the Quantitative Elements of Hydrogeology. 

 By Joseph Lucas, F.G.8., Hydrogeologist, late of H.M. Geological Survey. 



§ Percolation. 

 Divisions of the Rainfall Year. — Among observers of percolation Mr. Evans 

 divides the year into the winter half, October 1 to March 31, and the summer half, 

 April 1 to September 30. Messrs. Lawes and Gilbert take the harvest year from 

 September 1 to August 31. Mr. Greaves gives the amount for each quarter, and 

 for the year ending at each quarter — March, June, September, and October. Eber- 

 mayer divides the year into four quarters — 



Spring . . . March. 



Summer . . . June. 



Autumn . . . September. 



Winter . . . December. 



Giving his annual totals in respect of the twelve months, March — February. 



In a paper : read at the Meteorological Society, Mr. James Glaisher, F.R.S., 

 supplies materials for comparing these various methods. He shows that the 

 rainfall year divides itself into two halves, commencing March 1 and September 1, 

 thereby proving the sagacity of Ebermayer. 



Divisions of the Percolation Year. — The month of March contains the driest 

 ten-day, fifteen-day, and thirty-day periods in the year, and the months of March 

 and April the driest sixty-day period. The effect of this is manifested in the 



1 ' On the Fall of Rain on Every Day of the Tear, from; Observations extending 

 from 1818 to 1869.'— Proc. Met. Soc, vol. v. p. 87. 



K K 2 



