angles were determined by a set of sixteen readings of each angle on eight equi tant parts of the circle, and read alternately to right and left, and with teles erect and inverted. A phaseless target, made of black and white cloth strips se across a diamond-shaped iron frame, was placed directly over center of each stat Heliotroping was only resorted to over two lines of the system, the other wor hand permitting of the selection of suitable weather for observing.

Topography. The topography of the season was all done with transit and sta which, owing to the character of the country, was considered more expeditious economical than the plane table method. The topography was platted to seal the field by the topographers upon 8 by 10 inch sketch paper, a small sketch bo and celluloid protractor being carried along for the purpose. Thus the two meth were practically combined.

The stadia courses were traversed between triangulation stations, and any discr ancy of more than five minutes in azimuth, or 1 in 500 in distance, was corrected re-tracing the lines in the field. Elevations above lake surface were determined all stadia stakes and such other points as necessary to locate 10-foot contours.

The topography taken covered all clearings, settlements, and towns along mainland or on the islands, but along the wooded shore included only the locat of water line, top of bank, and the degree of slope of land back from bank. dense undergrowth and windfalls overhanging the high bluff shores, and the d timbered gullies, made even this very slow and laborious.

Hydrography. Sounding y.-Sounding flags were placed and located along the shores by topographers, and their positions computed, these serving to locate the soundin These flags were spaced from 600 to 800 meters apart along straight shores, and portionately closer around convex bends. Buoys were set opposite each flag distance of about one-half mile from shore. Soundings were made on line from e buoy to the flag above and below from a yawl keeping on line by range po picked up on shore. A transitman on shore at the flag opposite buoy located p tion of boat by pointings at intervals of about one minute, signals being giver identify the soundings located. The buoys were also located by pointings f three or more flags. Lines were sounded between buoys and from buoys to f opposite, with the Vidette, locations being made with sextants.

For offshore hydrography transverse lines were sounded between the islands the steamer at intervals of one-half to 1 mile, and located with sextants.

Mapping. Detail charts were projected in camp on a scale of 1 to 10,000, and positions of triangulation stations and stadia stakes platted as soon as compu The topography and soundings were platted by the assistants on such days as weather prevented field work. At the end of the season about two-thirds of season's work was on the maps.

RESULTS.

Triangulation. -Two measurements were made of the Red Cliff base line, the crepancy between the two being 0.01200 foot, or about 1 in 600,000. The n length of base reduced to sea level is 7,199.16567 feet, or 2,194.28503 meters. T sets of observations for azimuth were made over the line from Pike to Bayfield, a range of 3.77 seconds. Forty-seven triangles were closed with an average dise ancy inclosure of 1.79 seconds; 26 close large, average 1.81 seconds; and 21 sn average 1.75 seconds. Thirteen tertiary points, such as light-houses and churc were located from the secondary stations.

It was intended to connect the season's triangulation onto the primary sta Outer Island, and to compute the coordinates from that point, thus tying the directly onto the primary system of Lake Superior. This was found impossibl account of this station having caved off the bank. A station belonging to the system of secondary triangulation of the Apostle Islands, here called Oak No. 2. found and included in the new system. This was the only mark of the old sur discovered. The coordinates here given are derived from Oak No. 2, as taken the computation of Apostle Island triangulation 1871, making the same correct to coordinates as are made to the coordinates of A Outer Island (primary) for new values (1901 adjustment); i. e., corresponding to Outer Island (primary) tude = 47° 4′ 17.396", longitude = 90° 26′ 26.404".

Appended hereto is a sketch of the triangulation system: Table 1, Computatio triangles; Table 2, Geographical positions and azimuths of secondary stations; T 3, Geographical positions of tertiary points, with brief descriptions, and a h descriptions of the secondary stations.

ARRED CLIFF

Madeline No. 4.