310 Exploring Visits to the Sources of the Hudson. 
lakes from which they issue, as well as the upper course of the Bo- 
reas and its mountain lakes, are not found on our maps. From the 
stream last mentioned, the road ascends the Boreas ridge or moun- 
tain chain by a favorable pass, the summit of which is attained about 
four miles from Johnson’s. Between the Boreas and the main 
branch of the Hudson, we encounter a subordinate extension of the 
mountain group which separates the sources of the two streams, 
through the passes of which ridge the road is carried by a circuitous 
and uneven route. 
We reached the outlet of Lake Sanford about noon on the Ist 
of August, and found two small boats awaiting our arrival. Hav- 
ing embarked we were able fully to enjoy the beauty and gran- 
deur of the lake and mountain scenery which is here presented, 
all such views being, as is well known, precluded by the foliage 
while traveling in the forests. ‘The echoes which are obtained at a 
point on the upper portion of this lake, are very remarkable for their 
strength and distinctness. ‘The trout are plentiful in this lake, as 
well as in lake Henderson and all the neighboring lakes and 
streams. We arrived at McIntyre about 4 P. M., and the resources 
of the settlement were placed in requisition by the hospitable 
proprietors, for our expedition to the source of the Hudson. 
Barometrical Observations on the Rout. 
The following table shows the observations made with the barome- 
ter at different points on our rout, and the elevation above tide wa- 
ter as deduced from these observations and others made on the same 
days at Albany, by Matthew Henry Webster, Esq. No detached 
thermometer was used, the general exposure of the attached ther- 
mometers to the open air being such as to indicate the temperature 
of the air, at both the upper and lower stations, with tolerable accu- 
vacy. In the observations with the mountain barometer a correc- 
tion is here made for variation in the cistern, equal to one fiftieth of 
the depression which was found below the zero adjustment at thirty 
inches. : 
It is proper also to state, that the two mountain barometers made 
use of, continued in perfectly good order during our tour, and agreed 
well with each other in their zero adjustment, which is such as will 
give a mean annual height of full thirty inches at the sea level; 
but, like other barometers which have leather bottomed cisterns, are 
lable to be somewhat affected by damp and warm weather when 
