(l22) 
The Obferver, M ^/?^«^ 3 uotes } that,when he made this Ob» 
fervation , the River of Chartres, which runs very near from 
South to North, was betwixt him and the Rainbow § and that he 
flood Level with this River, whence he was diftant not above 
1 50. paces.* which he adds.thatthe Curious may the better julige 
of this Obfervation. 
A Relatwn 
Of an Accident by Thunder and Lightnhg^at Oxford, 
This was imparted by Dr .Wallis in a Letter 3 written at Oxford, 
May r 2. 1 666 . to the Puhlijher 3 as follows : 
I {haiiid fcarce have given you fo foon the trouble of another 
Letter, were it not for an Accident which hapnd here May io« 
I had that afternoon, about 4. of the dock heard it thunder at 
fome diftance. About y. of the dock the Thunder coming 
nearer to Us, it began to rain , and foon after (the rain withal! 
increafing) the Thunder grew very loud, and frequent, and with 
long ratling Claps (though not altogether fo great , as 1 have 
fome other times heard :) and the Lightning with flafhes very 
bright ( notwithftanding the dear day-light) and very fre- 
quent, (when at the thefafteft, fcarce a full minute between 
one flafh and another; many times not fo much, but a fe- 
cond flafh before the Thunder of the former was heard :) The 
Thunder for the moft part began to be heard about 8. or 
10. fecond minutes after the flafh; as I obferv’d for a great 
part of the time by my Minute- Watch : but once or twice 
I obferv’d it to follow r ( in a manner) immediately upon it, 
as it were in the fame moment ; and the lightning extream 
red and fiery. Ido not ufe to be much apprehenfive of Thun- 
der and lightning, but I was at this time ( I know not well, why?) 
very apprehenfive, more than ordinary, of mifebief to be done 
by it, for it feenfd to me to be very low and near Us(which made 
me fo particular , as to obferve the diftance of the flafh by the 
noife)and very frequent ? and bright, fo thatffiad it been by night 
as it was by day, it would have been very terrible. And, though 
I kept within doors, yet I fenfibly difeover’d a ftinking iulphu- 
reous fineil in the Air. About/, of the clock it ended, before 
which time I had news brought m@ of a Sad Accident upon the; 
water 
