On Fri, 1 Feb 2019 04:48:21 -0000 (UTC), arlen holder <
ar...@arlen.com>
wrote:
I've tried to discover an answer to your question via the OED.
No real success!
The use of the plural goes back hundreds of years originally with water
main(s).
main, n.1
8. A principal channel, duct, or conductor for conveying water,
sewage, gas, or (usually in plural) electricity. Cf. main adj.2 5a,
mainsborne adj. Also in plural: the public supply of water, (or
electricity, etc.) collectively. Also fig.
In N. Amer. usage usually only modified, as in water main(s), etc.
1628 in J. Irving Hist. Dumbartonshire (1920) II. 308
[Waterworks:] To repair the manis in the kirk vennal and south
vennal be causeying the same.
1727 R. Bradley Chomel's Dictionaire Oeconomique (Dublin ed.) at
Building Where any Stock-Blocks of Wood with Plugs, or any
Fire-Cocks, were made and fix'd on any Mains [etc.].
1763 Ann. Reg. 1762 120/1 Wooden pipes were inserted into the
mains in almost every street.
1808 Philos. Trans. (Royal Soc.) 98 125 The gas..is conveyed by
iron pipes into..gazometers,..previous to its being conveyed
through other pipes, called mains, to the mill.
1825 J. C. Loudon Encycl. Agric. 658 The use of both the large
and small mains is to feed the various trenches with water, which
branch out into all parts of the meadow.
1865 D. Masson Recent Brit. Philos. i. 15 It is not only
Britain..that the writer accuses of this folly of not drawing its
philosophy from the main.
1879 J. Tyndall Fragm. Sci. (ed. 6) II. xvi. 449 The electric
main carrying the outgoing current.
1894 Times 12 July 14/1 The stopcock..was placed in the service
pipe leading from the water main into the adjoining house.
1894 National Observer 189/2 Take the case of a lead-pipe led
into a block of houses from the iron main.
1895 S. P. Thompson & E. Thomas Electr. Tab. & Mem. 4 In factory
wiring it is often preferred to keep the positive and negative
mains far apart.
1921 Daily Colonist (Victoria, Brit. Columbia) 12 Oct. 3/1 (advt.)
10 acres on Island Highway, near station and city school, city
main passes property.
1936 Discovery July 203/1 It is still safer to switch off the
current at the mains.
1986 J. Townshend in A. Limon et al. Home Owner Man. (ed. 2) vi.
ii. 843 If you do disconnect light fittings, first turn off the
current at the main.
1989 C. S. Murray Crosstown Traffic iii. 67 Her sexuality wasn't
something turned on and off at the mains for any man's
convenience.
1992 Harrowsmith Aug. 13/1 If yours is an autonomous house, free
of the grid and the water mains, [etc.].
--
Peter Duncanson, UK
(in alt.usage.english)