696 REPORT— 1880. 



2. On the Temperature of Town Water-supplies. 

 By Baldwin Latham, G.E., M.Inst.G.E., F.G.S., F.M.S., §-c. 



In this paper tlie author pointed out that summer diarrhoea and cholera 

 became prevalent when the water-supply of a district arrived at a temperatiure 

 exceeding 62° Fahrenheit, and he showed that it Avas the changes which took place 

 in water when at a higli temperature that induced the diseases referred to, and 

 not atmospheric changes ; in corroboration of which he referred to districts in which 

 the water was invariably cold in summer, and which consequently were not subject to 

 epidemics of diarrhcea. Moreover, ia districts in which the supply, when distributed 

 through water mains, was from a well which was naturally cold at its source, as, 

 for example, in the district supplied by the Kent Waterworks Co., when compared 

 with the districts in London supplied from the river Thames, it was foimd that in 

 the Kent district, the source of supply being so much colder at its source than the 

 Thames supply in summer, the ground requned a higher degree of temperature to 

 raise the temperature of the Kent water to a dangerous point, and thus the inci- 

 dence of the disease in the districts supplied with Kent water fell later than in those 

 supplied with Thames water. If the cause of the disease were due to atmospheric 

 temperature, the incidence should have been identical in both districts. The author 

 further pointed out that great changes in the temperature of water were due to the 

 temperature of the ground at the depths at which the mains were laid ; that the 

 temperature of the ground might be made use of in a special apparatus patented by 

 Professor J. T. AVay and himself, by which water was made to descend to a depth 

 of about 25 feet, by means of a vertical tube driven or screwed into the groimd, so 

 that the temperature of water required for dietetic purposes was rendered nearly 

 uniform throughout the year.. A greater range than 5° would not practically occur 

 in such a tube ; whereas in C!roydon, where there was a constant water-supply, 

 and where the water was of nearly imiform temperature in the wells before 

 passing into the mains, the range in tlie temperature had been 27-6'', and a cistern 

 supply of the same water gave a range of 38-7°. By keeping the temperature of 

 the water between the limits of 49° and 5i°, by the "use of the apparatus referred 

 to, it was explamed by the author that summer diarrhoea could, in a great measure, 

 be prevented.' 



3. On Spontaneous Comhustion of Coals in Ships. By James Bamfield. 



SATURDAY, AUGUST 2%. 



The Section 'met and adjourned. 



MOJVDA Y, A UG UST 30. 



The following Reports and Papers were read : — 



1. Report of the Committee on Tidal Observations in the English Channel. 



See Reports, p. 390. 



2. Eepiort of tlie Committee on Patent Legislation. See Reports, p. 318. 



' The paper appeared at length in the Builder of September 11, 1880, and in the 

 Jovrnal of the Society of Artf of September 17, 1880. 



