The general object of the expedition is to make a geographic reconnoissance of as large an area as practicable in the St. Elias range, Alaska, including a study of its glacial phenomena, the preparation of a map of the region explored, and the measurement of the height of Mount St. Elias and other neighboring mountains. Observations should also be made and information collected on other subjects of general scientific interest as far as practicable. The purpose of these instructions is mainly to suggest the lines of investigation that give promise of valuable results, but it is not intended that they shall limit the director of the expedition in the exercise of his own discretion. GARDINER G. HUBBARD, _Chairman_, MARCUS BAKER, WILLARD D. JOHNSON, _Committee_. _Washington, D. C., May 29, 1890_. {195} APPENDIX B. REPORT ON TOPOGRAPHIC WORK. BY MARK B. KERR. In addition to the ascent of Mount St. Elias, it was part of the original plan of the expedition to make an accurate topographic map of the region explored. It was not, however, for this purpose proposed to divide the party or to deviate much from the most direct route to Mount St. Elias from Yakutat bay. Triangulation of fair precision was provided for. Details were to be filled in by approximate methods. Field-work began June 20 by the careful measurement of a base-line, 3,850 feet in length, near the point of landing, on the northern shore of Yakutat bay. Expansion was readily carried to the foot-hills, and several horizontal angles were taken to an astronomical station of the United States Coast and Geodetic Survey at Port Mulgrave. In the region of these initial triangles, work was done from a central camp; and topographic details were fixed with considerable precision by intersection and vertical angles. After the departure of the expedition from the Base Line camp, an accident to the transit made resort to an inferior instrument necessary, and, furthermore, as the region traversed proved to be ill-adapted to, and the line of travel too direct for, the proper development of a narrow belt of triangles, the anticipation of a degree of precision in the triangulation which would give high value to the determinations of position and altitude of the several peaks was not realized; but topographic map work, showing the general features, altitudes and location of the mountain ranges, valleys and glaciers, was extended over about 600 square miles. Within the approximate geometric control, stations were interpolated by the three-point method, and minor locations were multiplied by intersection and connected by sketch. The best meander possible under the circumstances was carried forward on the line of travel by compass directions and estimates of distance from time intervals. The work ceased August 22 with the abandonment of the instruments in a snow-storm of four days' duration on the eastern slope of Mount St. Elias.