10 FEBRUARY 1967, Page 15

SIR,—This appears in the Diary of John Evelyn under April

22, 1694 :

A fiery exhalation rising out of the sea spread Itselfe in Montgomeryshire a furlong broad, and many miles in length, burning all straw, hay. thatch and grass, but doing no harm to trees, timber, or any solid things, only firing barns or thatched houses. It left such a taint on the grasse as to kill all the cattle that eat it. 1 saw the attes- tations in the bands of the sufferers. It lasted many moncths.

I have been puzzled by this entry for many years. Could any of your readers advance a theory?

T. ROOK

Deerleap Cottage, The Green, Rowlands Castle, Hants