Various Notkes'. ' 
purpose : river water contains impurities visible to the eye ; spring 
lyater contains them in a state of actual solution, and therefore in* 
visible. From the former, the impurities will separate themselves 
almost entirely, by rest or by filti'ation ; from the latter they can- 
|iot be separated by means adapted to the demands of common life. 
“ London, which is extremely healthy for its size, has long been 
supplied with river water, and to this, more than to any other cir? 
cumstances, are the inhabitants indebted for the health they enjoy, 
though few of them ever take the trouble to filter the water they 
luse, even for culinary purposes. The city of Glasgow, which till 
lately had no supply of water but from wells, has at length the 
prospect of an inexhaustible supply from the river Clyde, by means 
of pipes and steam engines. Two companies have embarked in 
similar undertakings 5 one of them under the direction of Mr, 
Thomas Telford, civil engineer, undertakes to bring in a large 
supply from the eastward of the town ; the other company, under 
the direction of Mr. Robertson Buchanan, to bring in a similar 
supply from the westward. Both works are in considerable for=? 
wardness, and many houses are already supplied with pipes ; but 
the circumstance which demands most attention from the public, 
and which is our principal reason of mentioning these under- 
takings, is t/ie Jiltration of the %vbole mpfily of wuter^ by means of 
Teserixoirs comtructed for that fiurfiose. This salutary process is 
effected by making the water filter through sand and gravel from 
the large reservoir into which it is first elevated by the steam en- 
gine, into a second reservoir deposited a little lower, and from 
which the conveying pipes receive their supply. 
“ This is the first instance, we believe (and well deserving imi- 
tation), that has as yet occurred of water being filtered on so large 
a scale, and when its advantages, not only to the health of the in- 
habitants, but to bleachers, dyers, and all other manufacturers, are 
duly considered, we cannot doubt but that it will be„adopted in all 
future undertakings for supplying towns with water, Hitherto all 
branches of manufacture connected with the use of water have 
been obliged to be carried to the water, and the ne^essaij hands 
along with them, and much expence for carriage and extra labour 
has been added to the price ; but should this system become gene- 
ral, manufactures will be carried on where the necessary supply 
of labourers can he most easily procured, and where the goods so. 
manufactured can find the most ready market. 
We belie ve that the filtration of water intended for public supv 
