EWING, FLATHEAD COUNTY, ΜΟΝΤΑΝΑ.

Location of station: In extreme northwestern corner of State, about 35 miles northeast of Bonners Ferry, Idaho. It can be reached by trail to Buckhorn mines, thence along divide 4 miles to break-off, thence northeast down into the basin or meadows, thence ascending ridge in northwest direction, thence along ridge to summit.

Station mark: Copper bolt in loose rock, above which is cairn of rocks 4 feet high.

Location of station: On first summit northwest of Newton Pass, on trail between Sylvanite and Newton's ranch.

Station mark: Copper bolt in loose rocks, above which is cairn of rocks 4 feet high.

Location of station: Just north of Kootenai County, Idaho. Reached from the Mooyie Trail by a trail to Grierson's ranch; thence by Indian trail to small lake lying to the east; thence around lake to ridge; thence up ridge to station.

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Station mark: Copper bolt in solid rock, above which is a rock cairn 44 feet high.

[Latitude, 49° 00′ 03′′.60. Longitude, 116° 12′ 56′′.12.]

A secondary station near boundary post No. 78; best reached by trail from Clark Fork, Idaho, by way of the Homestake cabin, to Blue Creek; two hours' travel to cabin, one and one-half hours from cabin

to camp on Blue Creek. The ridge leading from Blue Creek to the

station can be ascended on the south side in one and one-half hours. Station mark: Copper bolt in rock, over which is a rock cairn 3 feet in height.

[Latitude, 48° 08′ 50′′.14. Longitude, 116° 02′ 59′′.84.]

TRANSIT STATION 949, NEAR IDAHO-MONTANA BOUNDARY LINE.

A secondary station on a large hill near boundary post No. 9, 64 miles south of international boundary.

Station mark: None.

Reference mark: Signal tree, distant 138 feet, azimuth to which is 308° 55'.

[Latitude, 48° 54′ 32′′.59. Longitude, 116° 03′ 01′′.05.]

DIVIDE (2).

This triangulation station is not on the meridional portion of the line, but on the crest of the Bitterroot Mountains, farther south, and was located in connection with the survey of the Bitterroot Forest Reserve.

It is on the main summit of the Bitterroot Range, on the boundary line between Montana and Idaho, 20 miles (air line) west of Grantsdale. It can be reached from the Lost Horse Pass (camp being at Twin Lakes) by following the northwest face of the mountain northeast from the Twin Lakes to the crossing of Moose Creek, thence up the creek to the Meadows. The peak lies to the northwest, about 2,000 feet above the meadow.

Station mark: A rock cairn 5 feet in diameter and 8 feet in length.

TRANSIT AND STADIA WORK.

The transit used was one manufactured by Young & Sons, of the type known as No. 10 mountain transit, the maker's number being 6838. The horizontal circle was 4 inches, and this circle, as well as the vertical circle, was graduated to read with verniers to 1'. The instrument was provided with a compass attachment, fixed stadia wires, and a tripod with extension legs. The extension legs were at times very necessary, as may be seen from Pl. VI. Two stadia rods, of seasoned white pine, three-fourths inch in thickness, 12 feet in length, and 4 inches across the faces, were made in Spokane. The lower portions of the rods were tapered to a point and shod with steel. The design of the rod was black on a white ground. (See fig. 1.) By a series of tests the stadia interval was found to be in the ratio of 1 foot on the rod to 100 feet horizontal distance, as nearly as could be determined, and the rods were graduated to even feet and tenths. The extreme divisions of the rods included 10 feet, and each tenth was divided into five parts, so that hundredths could be easily read by estimation. No numbers were placed on the rods. In practice the rods were held vertically, proper corrections being applied for reducing all sights to the horizontal.

There was no expectation of obtaining exact independent results for distances measured with the transit and stadia upon the basis of the stadia wires in the transit being set in the ratio of 1 to 100 and the