RoVAL Society. 121 
quantity of water that was loft in the fpace of 14 hours, when 
the air was very calm, in proportion to what evaporated when 
there blew a ftrong gale, tho' the experiment was made in a place 
as clofe from wind as could be well contrived 5 for which realbn, 
Mr. Halley does not at all doubt, that had the experiment been 
made, where the wind had come freely, it would have carried 
away at leaft three times as much, without the afliftance of the 
fun, which might perhaps have doubled it. By the fame expe- 
riment it like wife appears, that the evaporations in May^ J^ti^'^t 
jfuly^ and Augufty which are nearly equal, are about three times 
as much as what evaporates in the four months of Novembery 
jDecefyber^ January^ and Felrua^y, which are likewile nearly 
equal 5 3farcb and April anlwering almofl to September and 
OBcher. This fleece of vapurs in calm weather, hanging on 
the iurface of the water, is the occafion of very flrange appearances, 
by whole refraction, difttring from that of the common air, every 
thing appears raifed, as houles like fteeples, /hips as if on land 
above the water, and the land elevated, and, as it were, lifted 
from the fea, and often feeming to overhang. And this may 
give a tolerable account of feeing the cattle at high-water in the 
Jfle ofUozi from Greerrjoicb, where none arc to be feen at low- 
water; which lome have endeavoured to explain, by fuppofing 
the I/Ie of Dogs to be railed by the tide running under it 3 but 
the vaporous effluvia of water, having a greater degree of refrac- 
tion than the common air, may fuffice to bring thole rays down 
to the eye, which, when the water is retired, and the vapours 
fubfide therewith, pals above 5 and confequently objeds feen at 
one time, may be conceived to difappear at another time. 
A Stove for prefervitig Plants ^ by Sir Dudley CuUum. Phil. 
Tranf N° 2I2. p. 191. 
SI R Dudley made a ftove in his green-houfe, according to 
Mr. Evelyns invention, publiflied in the Calemlariiwt Hor- 
tenfe-j he laid his pipes of crucible earth, not too near the fire- 
grate, which was about 16 inches j he made a trench the 
whole length of his houle under the paving, about 18 inches m 
breadth, and as many in depth, covered with an arch of bricks ; 
at the other end of the trench, having an iron plate about 18 
inches fquare, to take off and put on, with a round hole at each 
corner, of about three inches diameter, with a lid to Aide open 
and fhut; fo that by opening any of thele holes, or all of them 
mere or lefs, or tc^king off the whole plate, a certain quantity of 
air might be admitted to blow the fire more or lefs; and for the 
more equal diftributing the air at its admiffion thro' the houfe, he 
infected his pipes into'a channel all along the wall, at the end of 
V^L. III. Q^ the 
