431 Scientific Intelligence. 
5. The minimum temperature of the depths of the Mediterranean is 
equal to the mean temperature of the winter 
In the southern part the temperature decreases through the year, toa 
depth of 35 to 440 yards. In the northern part it increases during the 
winter to that depth. It seems consequently that the cold temperature 
below depends on the descent of the upper cold strata during winter, 
and not on the entrance of the waters of the ocean 
63. Boiling point of Water at different heights ; rae M. V. Reenavtt, 
(extracted from Ann. de Chim. et de Phys., xiv, 1845, 196.)—The fol- 
lowing table has been made out by M. V. Reenavtr to aid in determin- 
ing heights by the boiling point of water, a method recommended alike 
by its simplicity and the portable character of the instrument, and now 
very commonly adopted in preference to the barometer. The calcula- 
ted results are shown to vary less than half a line in the height of the 
barometric column from those by observations. 
. M. Reenavtr states that the thermometer should be made of the 
best erystal glass, as others dilate irregularly. They are graduated 
~ from 75° to 100° C., (equivalent to 167° to 212° Fah.,) and the follow- 
ing is the method atlopted for this purpose. As much mercury is in- 
troduced in the usual way as will stand one third up the stem when 
placed in melting ice ; this point (designated n) is accurately marked. 
The tube is then placed alongside of another graduated thermometer in 
a large vessel full of water, kept agitated, and exactly at 20° C. (68° 
Fah.); and the height of the mercury (n’) corresponding to the degree 
of temperature (¢) indicated on the graduated scale is noted. 7 
will then give the value of a degree. A portion of the mercury is next 
expelled, so that it will reach towards the top of the tube when in boil- 
ing water, and the tube is closed as usual. It is then placed in the vapor 
of boiling water under a pressure of about 760 millimetres, and the 
point at which the mercury stands (n”) is noted, and also the exact 
temperature (T). The value of a corrected degree may then be obtain- 
ed by the following formula :— 
n' — 
i + diss _— 
4 fy 
6480 
The instrument is made of brass tubes that slide into one another 
a spy-glass, and is but six inches long when closed up, but may be 
out to a length of fifteen inches. The lower part, which contains 
er to be heated, is one and one-eighth inches in diameter. This 
is inserted i in a large cylindrical vessel, which has a lamp at bottom. 
The thermometer i is dropped down into the vapor just above the surface 
of the - water. 
