SECTIONAL TRANSACTIONS.— E. 573 



commercial quarter in modern times has been responsible for the withdrawal of the 

 populace to higher, healthier and more diversified areas away from the river, lea\Hng 

 warehouses and business establishments in possession of the level, low-lying alluvial 

 tracts. • 



Mr. A. W. McPherson. — The Water Supply of the Glasgow District. 



In this paper it was remarked that since early times the question of water supply 

 had been one of pre-eminent importance — not surprising when one remembers that 

 roughly 80 per cent, of the human frame is composed of water. 



This discussion involved the consideration of several factors closely inter-related. 



1. Topography. — The proximity of high land masses greatly facilitates the conduc- 

 tion of water by gravitation — in this respect the Glasgow district is emipcntly suited, 

 being almost entirely surrounded by upland areas. Passing from south to north 

 these are : the Renfrewshire Uplands, separated from the Kllpatriek Hills and from 

 the Campsie Fells by the valley of the Clyde, which is very narrow at this point. 

 Further north there is the western extension of the great Valley of Strathmore, north 

 of which lies the moxmtainous region at the south-western end of the Grampians. 



2. Geology. — This is important, for the nature of the rocks often seriously impairs 

 the quality of water available. 



The volcanic masses of the Renfrewshire Uplands and of the Campsie Fells and 

 liilpatrick Hills are separated by the Carboniferous rocks of the Lanarkshire coalfield 

 area, which is narrow at Glasgow, but widens out towards the east. The Valley 

 of Strathmore is based almost entirely on the Old Red Sandstones, north of which, 

 and separated from them bj' the Highland Bomadary Fault, is a region of durable 

 and almost impermeable Primary rocks. 



Thus the prevailing rocks of these upland masses being either igneous or of primary 

 formation, tlie water given off is very soft and free from mineral impregnation — 

 largely accounting for the early establishment of bleaching mills at the fringes along 

 the break of slope. 



3. Rainfnll is closely related to topography, as was seen from the map constructed 

 by the speaker. Rainfall increased with altitude, e.g. over 60 ins. on the Campsies 

 and over 110 ins. in the N.W. corner of the Loch Katrine Reception Area. On the 

 plain the rainfall was found to decrease with passage eastwards from about 50 ins. 

 at Dumbarton to less than 35 ins. in the eastern part of Glasgow. 



In such a region it is obvious that the factors of evaporation and permeability are 

 negligible. 



Therefore the Glasgow area is a region eminently suited for an abundant supply 

 of good water by gravitation, yet it was not until the latter part of last century that 

 this occurred. Before the present mode of supply was developed two eras are 

 recognisable : — 



1. The ' Well era ' up till 1806, in which the water supply was obtained from a 

 number of wells (oVer thirty) which yielded very unsatisfactory water of doubtful 

 quality and origin. 



2. The 'Water Company Era,' 1806-1859, in which the water supply was obtained 

 from the Clyde and passed through very crude filters to the town reservoir. The 

 water grew progressively unwholesome with the increasing sewage discharge into the 

 river from the rapidly developing coalfield area further upstream. 



Numerous alternative schemes of supply were suggested, only one of which 

 materialised — the Gorbals Water Company — utilising the headwaters of the Brock 

 Bum. This scheme is still in existence, and serves the useful purpose of supplying 

 places at high elevations, or at distances from Glasgow to which it would be Isoth 

 difficult and expensive to send Loch Katrine water. 



The attention of all investigators was directed to the area north of Glasgow because 

 of— 



1. Suitable elevation close at hand. 



2. Very soft water. 



3. Little moss or cultivated land, therefore a low content of organic matter. 



4. No mines, therefore no apprehension of damage to the works through subsidence. 

 The Loch Katrine scheme w^as preferred to Loch Lubnaig because — 



I. It is higher — thus facilit<ating the conduction of water over the intervening 

 valleys and ridges. 



