vel might exist between the St. Lawrence at Metis and
at the river Du Loup. Four days of contemporaneous observations were
therefore made at each with a view to the solution of this question.
The idea of a difference of level was not sustained by the operation.

The heights of the river stations were measured in each case to the
highest mark left by spring tides, and half the fall of that tide as
given by Captain Byfield has been added in all cases as a reduction to
the mean level of the sea. Opportunities were offered in a few instances
for testing the accuracy of the method by different barometers used by
different observers at different days on the same point. No discrepancy
greater than 7 feet has been thus discovered. In other cases the same
observer returned and observed at the same places, and here a similar
congruity of result has been found to exist.

The whole of the calculations have been made by the formulae and tables
of Bailey. Before adopting these their results were compared in one
or two instances with those of a more exact formula. The differences,
however, were found so small as to be of no importance, amounting in the
height of Lake Johnson to no more than 5 feet in 1,007. The original
record of the barometric observations, each verified by the initials of
the observer, have been deposited in the State Department.

25. The paths pursued by the traveling parties were marked by blazing
trees. The position of the barometer at each place of observation was
also marked. The operation was a search for the boundary line in an
unknown country, hence it rarely happened that the path of the parties
has pursued the exact dividing line of the waters of the St. Lawrence
and the Atlantic, but has been continually crossing it. The maps
herewith submitted and the marks by which the line of the survey has
been perpetuated would have enabled a party sent out for that especial
purpose to trace the boundary on the ground without difficulty other
than that arising from the inacessible character of the country.

26. The commissioner can not speak in too high terms of the industry and
perseverance manifested by the engineers and surveyors employed on this
division, and in particular of the skill and intelligence of the two
first assistants. Circumstances had prevented the receipt of portable
astronomic instruments which had been ordered from Paris and Munich, and
an instrument formed by the adaptation of a vertical circl