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XXXV. A Letter from Mr. George Ed- 
wards, F. R. S. to Thomas Birch D. D . 
Secret . R. S. concerning An Obfervation 
7nade by him in Op ticks. 
Sir, 
Read j Jg ne l6, X Having lately accidentally difcovered,. 
X that the fhadows of things floating 
in water, a little below its furface, are reflected from 
the air above the water more ftrongly (to my appre- 
henfion) than objeds above the furface of the water 
are reflected from the water j and confequently, that 
fillies playing beneath the furface of a ftill water, 
may fee their images diftindly playing in the air, with 
this advantage over men, who view their faces in the 
water ; for things in air, that are reflected from the 
water, muft have, when placed over the water, have 
their dark or fhadowed fides reflected from it,, which 
renders the images obfcure. On the contrary, the in- 
habitants of the waters have almofl: a hemifphere of 
light falling on their upper fides, which are the fldes, 
that are reflected from the air, which confequently ren- 
ders fuch images lighter, and more ftriking to the eye, 
than refledions of obfcured things in air, when refled- 
ed from the water.. As I have never heard of, or 
read, any account of this difcovery, I imagine it may 
be new : but you, Sir, in far more extenfive reading, 
may be acquainted with fuch a difcovery. If fo, I ac- 
knowledge my ignorance of it 5 and aik pardon for 
giving. 
