138 MEM O I VLS of the 
chief organ of refpiration, was in this fubjedl free in its a6\ion"i 
But it is likely this perfon breathed very ihort, the quicknels of 
the returns fupplying the defedt of a large draught of air at once; 
and po{Iibly the Foramen Ovale might continue open, and by it 
and the Caiialis Arteriofus the blood might pafs from the Cava to 
the Aorta, and but a part of it pafs thro* the lungs. 
^ Water-fpout 5 hy Mr. Zach. Maine. Phil Tranf. N° 215. 
p. 28. 
THESE appearances are frequent abroad, tut very feldora 
or never to be feen with us, tho' Ibme pretend to have leen 
them in the tDow^JS ; the French call them Trombes, poflibly from 
their figure, and the noife they make, that term fignifying a 
kind oi Hummifig ^top , they are certain elevations of water, during 
florms and terppefts, reaching from the furface of the fea to the 
clouds^ they happen feveral ways 5 fometimcs the water is feen to 
boil, and raile it felf for a conliderable fpace round, about a foot 
from the furface; above which appears, as it were, a thick and 
black fmoke, in whofe middle is oblerved a fort of flream or pipe, 
refembling a tunnel, which rifes as high as the clouds, at other 
times thefe pipes or tunnels are oblerved to come from the clouds, 
and fuck up the water with great noife and violence ; they move 
from the place where they were firft collected, according to the 
motion of the wind, and difcharge themfelves fometimes into the 
lea, to the unavoidable deftru*ilion of luch ihips, as are in their 
way, if they be fmall veflels, and to the endamaging even of large 
fhips ; fometimes they fall on the fhore, beating down all they 
meet with, and railing the land and ftones to a prodigious height; 
ufually guns are fired at them loaded with a bar of iron 5 and if 
they are fo happy as to llrike them, they prelently difcharge their 
water with a mighty noile, without any farther mifchief. 
A Tropofition of general ufe in Gunnery ; hy Mr. Edm. Halley. 
Phil. Tranf. N^2i(J. p. (?8. 
IT was formerly the opinion ^of thole concerned in artillery 
that there w^s a certain requifite of powder for each gun, and 
that in mortars where their dillance was to be varied, it muft be 
done by giving a greater or lefler elevation to the piece ; but now 
our later experience has taught us, that the fame thing may be 
more certainly done and readily performed, by increafing and di- 
minifliina the quantity of powder, whether regard be had to the 
execution to be done, or to the charge of doing of it ; for when 
bombs arc dilbharged with great elevations of the mortar, they 
&.I1 too perpendicular, and bury themfelves too deep in the 
ground, 
