88 M O N T - 
mathematical apparatus. That he might he perfectly at 
liberty to pafs the night on what part of the mountain lie 
pleated, he carried a tent with him ; and he and his com¬ 
pany llept in it the fird night on that eminence which is 
fird met with, and which is on the fouth of the priory, 
about a mile perpendicularly above the village. 
Hitherto the journey was free from danger, or even dif¬ 
ficulty ; the road being rocky, and covered with grafs ; 
but thence upwards it was either wholly covered with 
fnow, or confided of the mod flippery ice ; fo that the 
fecond day’s journey was attended with many difficulties. 
The ice valley on the fide of the hill mud be pafl’ed, in 
order to gain the foot of that chain of rocks bordering on 
the perpetual fiiows that cover Mont-Blanc. The pallage 
through this valley is interfered with numerous wide, 
deep, and irregular, chafms, which can only be eroded by 
.means of bridges naturally formed of fnow, and thefe 
often very ilender, extended as it were over an abyfs. One 
of the guides had almod perifhed here, as he, with two 
others, Went to examine the road. They had the precau¬ 
tion to tie themfelves together with a long rope, and lie in 
the middle had the misfortune to have the fnow-bridge, 
over the wide and deep chafm, break under him, fo that 
lie remained fufpended between his two comrades. M.de 
SaufTure and his retinue pafifed very near the opening 
through which this man had fallen, and fiiuddered at the 
danger in which the poor fellow had been involved. The 
guides were'defirous of palling the night near one of the 
rocks on the fide of this valley ; but, as the loftieft of them 
is at leall 1400 yards perpendicularly lower than the fum- 
mit of the mountain, M. de Sauffur-e was defirous of af- 
cending higher ; in confequence of which it would be'ne- 
ceffary to encamp on the fnow : but he found it difficult 
to convince his companions of the practicability of the 
plan. They imagined that, during the night, an inftip- 
piortable cold prevailed in thofe heights, which were eter¬ 
nally covered with fnow, and they were ferioufly afraid 
of periffiing. By proper encouragements, however, he 
induced them to proceed ; and at four in the afternoon 
they arrived at the fecond of the three plains of fnow 
which they had to pafs. Here they encamped at the height 
of 3100 yards above the priory of Chamouni, and 4250 
yards above the level of the fea, which is about 200 yards 
higher than the peak of Teneriffe. They did not proceed 
to the lad plain, on account of the day having been far 
advanced ; and they were alfo apprehenfive of expoling 
themfelves to the fitoals of ice and fnow which are fre¬ 
quently tumbling from the fummit of the mountain. They 
dug a deep hole in the lnovv, fufficiently wide to contain 
the whole company, and covered its top with the tent. In 
making this encampment, they began to experience the 
effects of the rarity of the atmofphere. Robud men, to 
whom feven or eight hours walking or climbing were an 
abfolute nothing, had fcarcely railed five or fix ffiovels of 
fnow, before they were under the neceffity of reding and 
relieving each other. One of them, who had gone back 
to fill a cafk with fome water he had feen in one of the 
crevices, found himfelf fo much disordered, that he re¬ 
turned without the water, and palled the night in great 
pain. Even M. de Sauffure, who was accudomed to the 
air of mountains, was exbauded with the fatigue of making 
his meteorological obfervations. The principal inconve¬ 
nience, next to laditude, which the thinnefs of the air 
produces, is an exceffive third, which they had no means 
of allaying but by fnow water. 
This region of the mountain prefents to the view no¬ 
thing but fnow of the pured and mod dazzling whitenefs, 
forming a very lingular contrad with the fky, which ap- 
peras remarkably black. “ No living creature (faysM. 
de Sauffure) is to be feen in thefe defolate regions, nor is 
the lead trace of vegetation to be difeovered. it is the 
habitation of cold and lilence ! When I reflected that Dr. 
Paccard, and his guide Jacques Balmat, who fird vidted 
thefe deferts, arrived here at the decline of the day, with¬ 
out Ibelter, without abidance, and wholly ignorant where 
BLANC. 
or how they were to pafs the night, without even the cer¬ 
tainty that it was podible for men to exid in the places 
they had undertaken to vidt; and yet that they were able- 
to pur/ue their journey with unremitted intrepidity, I 
could not but admire their drength and courage. My 
guides were fo firmly prepolfeffed with the fear of cold, 
that they fhut up every aperture of the tent with the ul- 
mod exaClnefs; fo that I buffered very conliderably from 
the heat and the vitiated air, which had become highly 
noxious from the breaths of fo many people in a fmall 
room. I was frequently obliged, in the courfe of the 
night, to go out of the tent, in order to relieve my breath¬ 
ing. The moon flione with the blighted fplendour, in the 
midd of a d<y as black as ebony. Jupiter, rayed like the 
fun, arofe from behind the mountain in the ead. The 
light of thefe luminaries was reflected from the white 
plain, or rather bafon, in which we were fituated ; and, 
dazzling, eclipfed every ftar, except thofe of the fird and 
fecond magnitude. 
“ We began our afeent (continues M. de Sauffure), 
early in the morning, to the third and lad plain, and then 
turned to the left, in our way to the highed rock, which 
is on the ead part of the fummit. On this peak the at¬ 
mofphere js fo rare, that a man’s drength is exhaufted with 
the lead fatigue. When we came near the top, 1 could 
not walk fifteen or fixteen deps without dopping to take 
breath; and frequently perceived myfelf fo faint, that I 
was under the necedity of fitting down from time to time ; 
and, in proportion as I recovered my breath, I felt my 
drength renewed. All my guides experienced finiilar 
fenfations, in proportion to their refpeCtive conditutions. 
We arrived at the f ummit of Mont-Blanc at eleven o’clock 
in the forenoon ; and enjoyed the unfpeakably grand f'pec- 
tacle which was under our eyes. My guides now pitched 
my tent, and were fixing the apparatus for the experi¬ 
ments I had propofed to make on boiling water ; but, when 
I came to difpofe my indruments for that purpofe, I was 
obliged, almod at every indant, to delid from my labours, 
and turn all my thoughts to the means of refpiration. 
When it is confidered that the mercury in the barometer 
was no higher than (ixteen inches and aline (17-145 inches 
Engli(h), and that this air had confequently little more 
than half the dendty of that on the plains, the breathing 
mud neceffarily be increafed, in order to caufe, in a given 
time, the paffage of a diffident quantity of air through 
the lungs. I remained on the fummit till half pad three ; 
and, though 1 did not lofe a dngle moment, I was not able 
to make all thofe experiments in four hours and an half 
which 1 have frequently done in lefs than three on the 
fea-fide. However, 1 made with great exaftnefs thofe 
which were mod effential. 
“ I am perfuaded, however, that the indifpofition, in 
confequence of the rarity of the atmofphere, is different in 
different people. For my own part, 1 felt no inconveni¬ 
ence at the height of 4000 yards, or nearly two miles and 
a quarter ; but I began to be much affected when I was 
higher in the atmofphere.” 
From this furvey it lias been afeertained, that the fum- 
mit of the mountain is a ridge nearly horizontal, lying ead 
and wed : the dope at each extremity is inclined from 
twenty-eight to thirty degrees, the fouth dde between fif¬ 
teen and twenty, and the north about forty-five or fifty. 
This ridge is fo narrow as fcarcely to allow two people to 
walk abread, efpecially at the wed end, where it refembles 
the roof a houf'e. It is wholly covered with fnow ; nor is 
any bare rock to be feen within 150 yards of the top. The 
fnrface of the fnow is fcaiy, and in fome places covered 
with an icy crud, under which the fnow is dudy, and 
without confidence. The highed rocks are all granites ; 
thofe on the ead fide are mixed with deatites ; thofe on 
the fouth and wed contain a large quantity of fchoerl, and 
a little Lapis corneas. Some of them, efpecially thole 011 
the ead, feem to have been lately differed with lightning. 
M. de Sauffure has given us the height of the barome¬ 
ter on tiie top of Mont-Blanc. Augud 3, at noon, 16 
inches. 
