Before putting the trace of the river thus derived upon the map it was adjusted to correspond with the results of astronomical observations for latitude and longitude at twelve intermediate points between its mouth and the outlet of Lake St. Francis.  Its three principal lakes, viz, Pettiquaggamas, Petteiquaggamak, and Pohenagamook, were triangulated and sounded as exhibited by the maps of detail yet to be handed in of the operations of this division.

A profile of the river, exhibiting the slope of the country through which it flows, was obtained by barometric observations made at fifteen points between its mouth and the bridge where it is intersected by the Grand portage road.

A connection was made with Long Lake, a tributary to Lake Temiscouata, by a chained line from a point on the St. Francis 2 miles below the mouth of Blue River to the western shore of Long Lake, by which it was ascertained that the shore of this lake approached within 2-3/4 miles of the river St. Francis.

The outlet of Lake Pohenagamook was reached in a distance of 49-3/4 miles from the mouth of the St. Francis following the sinuosities of the river on the 18th of October.

A camp was established on the southwest shore of the lake at its outlet for the purpose of making the necessary astronomical observations to determine the latitude and longitude of this position.  Ten days were spent here for this object, out of which we had only three nights that were favorable for observation.  These were improved as far as possible, and the results obtained, combined with those obtained by Captain Talcott’s parties on the Northwest and Southwest branches of the St. John, have furnished the elements for laying down upon the general map the straight lines which show the boundary as it is required to run between the highlands and the river St. John under the treaty of 1842.  These furnish data for an accurate exhibition of the extent of territory included by this portion of the boundary as fixed by that treaty.

The south shore of Lake Pohenagamook forms an angle of about 100 deg. with the direction of the stream which flows from it, and marks with great certainty the point at which, according to the late treaty, the straight line is to be commenced in running the boundary southwestward to the Northwest Branch of the river St. John.

The work of this division was connected with that of Captain Talcott’s division of the preceding year by noting the position of a common point on the western shore of Lake Pohenagamook near its head.

The commissioner and his party reached the Grand portage, or British military road, where it crosses the river St. Francis on the 2d of November, and connected their work with that of Professor Renwick’s division of the preceding year at the bridge near Fournier’s house.

Observations were also made at this bridge for the latitude and longitude, when the weather was favorable, between the nights of the 2d and 5th of November, and a connection was made in longitude with the meridian of Quebec by comparisons of the local time with three chronometers transported from the first to the last mentioned place between the 6th and 10th of November.