THE PLANTS OF THE GRAMPIANS. 57 
observed. Occasionally, a rest was made, the strap and in- 
strument taken off, and suspended in the shade of a tree, 
rock, hollow in the ground, umbrella, or even handkerchief 
only, if no better shade could be obtained. After allowing 
the instrument to lose the warmth acquired by personal con- 
tact, or from the rays of the sun, notes of the pressure of the 
atmosphere, of the temperature of the sympiesometer by its 
attached thermometer, and of the temperature of the air by a 
separate thermometer, were again written down. If the 
thermometers were graduated exactly, and sufficient time al- 
lowed on such occasions, the attached and detached would 
show the same temperature, but practically they were fre- 
‘quently different by a degree or two. After making these 
notes, I again ascended, still writing down the names of 
plants as they successively came under view; and, on gaining 
a higher elevation, another stoppage was made, and the pro- 
cess repeated. On attaining the summit of the hill, after 
such alternate ascents and stoppages, the process of ascer- 
taining the temperature of the air and instrument, and the 
pressure of the atmosphere, was again repeated ; and as com- 
plete a list as possible was made of the plants growing close 
round the summit. On the descent, the same plan was pur- 
sued, except that the names of all plants not observed on the 
summit were duly entered in the note book, in the order of 
their first appearance, that is, of their highest observed limits 
along the track passed over. On again reaching the inn, the 
indications of the thermometers and sympiesometer were a 
second time taken at the same place. 
The results of the excursion appeared in my note book, in 
the form of a list of mountain plants, their names set down 
in accordance with their lowest observed stations,—a list of 
Plants seen on the summit,—and a list of all plants seen in 
descending, their names following each other in accordance 
with their highest observed stations. At intervals, the co- 
umn of names was interrupted by the notes taken from the 
instruments used, and by means of which the height of each 
resting place could be calculated at leisure. A comparison 
F 
