Notation - multiple time signatures

[Richard Barrett]

Surely that's just Stravinsky's way of saying that the two solo violin quavers (hence he uses 2/8, not 4/16, I guess) should take up as much time as the 5 semiquavers of the first and second violins.

Indeed. A more elegant and consistent way to notate this would have been to put a bracket marked 4:5 over the violin parts where they have 4 semiquavers in a bar, and 6:5 where they have 3 quavers. Such notations were in frequent use by the time Stravinsky wrote Requiem Canticles - see Stockhausen's Klavierstücke I-IV for some particularly complex early examples.