[ 492 ] 
of Laye (4) and Manna, were all cracked by them ; 
and the works at the fugar- plantation (f) received 
confiderable damage. The ground opened near the 
qualloe (6) at Bencoolen, and up the River in feveral 
places j and there iffued therefrom fulphureous earth* 
and large quantities of water, fending forth a moft 
intolerable ftench. Poblo Point (7) was much cracked 
at the fame time ; and fome doofoom (8) in-land at 
Manna were deftroyed, and many people in them. 
Thefe are all the ill effe&s, that have come to our 
knowlege ; but, it is reafonable to fuppofe, not all 
the damage, that has happened upon the ifland. 
LXIII. Concerning the Fall of TV ater under 
Bridges . By Mr. J. Robertfon, F. R. S. 
Read Jan. 19, rjOME time before the year 1740^. 
1 75 ®- t ] ie problem about the fall of water, 
occafioned by the piers of bridges built acrofs a river,, 
was much talked of at London, on account of the 
fall that it was fuppofed would be at the new bridge 
to be built at Weftminfter. In Mr. Hawkfmore’s and 
Mr. Labelye’s pamphlets, the former published in 
173^ 
(4) Laye houfe or factory is about 30 miles to the northward of 
Marlborough, and Manna houfe orjfadtory fifty miles to the fouth- 
ward. 
(5) The fugar-plantation is five or fix miles from Marlborough.. 
(6) The qualloe is the country word for a river’s mouth. 
(7) Poblo Point lies about three leagues to the fouthward of 
Marlborough. 
(8) Doofoons are villages. 
