28 
Example 3.— h = 30*037 a or d = 55 
£ v = 29-508 a x or<T = 55.5 
Form. 12 3 4 
490 491 490 492 
Example 4. — h = 30*037 a or d = 58*5 
# = 29-508 or d N = 55*5 
Form. 1 2 3 4 
481-7 481*3 481-8 — - 484*4 
In commenting upon the examples, Mr. Sanders said that the second 
and third examples were calculated from observations made by him at 
Cheddar, at an excursion taken by the Society on Aug. 29th, 1865 ; the 
fourth was an experiment, to show the importance of observing tempera- 
ture, for the barometric heights were the same as in example 3, and yet 
there was a difference of 9 feet in 480. At a future meeting, Mr. Sanders 
hoped to describe the " Practice " of the mountain barometer, as well as 
the construction of, and amount of reliance to be placed upon, the Aneroid 
barometer, and also to explain an important correction, mentioned in no 
published treatise, for the normal diurnal change in the barometric column. 
The Vice-President, in thanking Mr. Sanders for his admirable paper, 
regretted the absence of his colleague, Canon Moseley, who would have 
been better able than he was to discuss it. 
Some conversation ensued upon aneroid barometers, the determination 
of the relative densities of air and mercury, &c, and a further explanation 
of some points in the theorem was given by Mr. Sanders in reply to the 
inquiries of members. 
Mr. W. W. Stoddart, F.G.S., then exhibited with the aid of the 
oxy-hydrogen microscope, some beautifully delicate specimens of sea-weeds 5 
showing the fruit, &c. The following directions for the process of mount- 
ing them were given :— Float the sea-weed out in the usual manner, dry 
almost completely with blotting paper, transfer to a glass plate, and moisten 
with turpentine ; after some time, cover the sea-weed with a thin mixture 
of Canada Balsam and Chloroform, place a second glass plate on the top, 
allow the whole to stand for a week or two, and varnish the edges with any 
suitable cement. Mr. Stoddart said that this method could be applied to 
plants, if they were not too thick, to moths and other insects, softening 
the bodies, when required, with potash. He admitted that the minute 
structure of the sea-weed was altered, owing to the contraction of the 
cells caused by the greater density of the medium ; this, however, could 
