189 
the same, viz., 438°, the wind at the time was W.S.W., and the 
weather clear and fine. It was the same on the 24th December. 
The greatest difference in the temperature of air and water was on 
the 25th (Christmas Day), when that of the air was 35°, and of the 
water 44°°3. Onthe 1st January, 1889, the difference is more 
remarkable, viz., air 30°°6, water 40°, and the same was the case 
on the day following, viz., air 29°, water 38°°5, with the wind 
N.E., and weather fine. A sudden rise of temperature occurred on 
the 8th January, when that of the air was 39°-8, and of the 
water 38°:2, somewhat colder than the air; the wind South and 
the weather fine. The same was the case the day following, viz., 
air 45°, water 41°°5. 
Asarule the temperature of the water has not increased so 
rapidly as that of the air. On the 5th May, for instance, the air 
was 69° and the water 57°:2; the same on May 9th, viz., air 62°, 
water 57°. In February, with snow on the ground, the tempera- 
ture of the air varied from 25°°8 to 34°°8, and that of the water 
from 34°-6 to 39°°5, the wind at the time being E. to N.E. 
Speaking generally, it is observed that with the wind South 
or 8.W., and rain falling, the temperature of air and water differ 
only one or two degrees. 
XXIV.—White Rhinoceros Horn.—By T. T. Hitrier, M.R.C.S., 
Eng. 
FEB. 10, 1887. 
A letter was read announcing that Mr. Hillier had secured a 
horn of the white rhinoceros, which had been found at Ramsgate 
in a deposit of Romano-British date. The Romans believed in the 
power of shavings from these horns to show the presence of poison 
in the wine cup: and the Chinese have the same belief at the 
present day. 
XXV.—Recent Fall of Rock at Niagara Falls—Communicated by 
W. P. Marsnatt, Esa. 
Mr. J. Reid read a short note relating to the great fall of rock 
that had recently occurred at Niagara, which was illustrated by 
approximate sketch maps, showing the present state of the Niagara 
Falls, and the state two hundred years ago, which is the earliest 
records known, from a visit of Father Hennepin. The communica- 
tion had been received from Mr. W. P. Marshall, of Birmingham, 
who in 1884 had visited and well studied the condition of the 
Falls, and by his engineering knowledge had been able justly to 
