A neat little observatory was erected on the lower terrace, not far from the store-house, and it was promptly put to use; and an accurate survey of the harbor and bay, with soundings, was made as soon as the ice was strong enough to bear our weight. The observatory was a frame structure eight feet square and seven high, covered first with canvas and then with snow, and was lined throughout with bear and reindeer skins. In it our fine pendulum apparatus was first mounted, and Sonntag and Radcliffe were engaged for nearly a month in counting its vibrations. It was found to work admirably. Upon removing this instrument, the magnetometer was substituted in its place, upon a pedestal which was not less simple than original. It was made of two headless kegs, placed end to end upon the solid rock beneath the floor, and the cylinder thus formed was filled with the only materials upon which the frost had not laid hold, namely, beans. Water being poured over these, we had soon, at ten degrees below zero, a neat and perfectly solid column; and it remained serviceable throughout the winter, as no fire of any kind was allowed in this abode of science.[2] [Footnote 2: It is proper to mention here that the pendulum and magnetic observations, as well indeed as all others in physical science, were, upon my return, sent to the Smithsonian Institution at Washington, and were placed in the very competent hands of Mr. Charles A. Schott, Assistant in the United States Coast Survey, to whom I am indebted for most able and efficient coöperation, in the elaboration and discussion of my materials, preparatory to their publication in the "Smithsonian Contributions," to which source I beg to refer the reader for details.] [Illustration: PORT FOULKE and VICINITY North Greenland ] [Sidenote: SCIENTIFIC WORK.] In order to obtain an accurate record of temperature, we erected near the Observatory a suitable shelter for the thermometers. In this were placed a number of instruments, mostly spirit, which were read hourly every seventh day, and three times daily in the interval.[3] In addition to this, we noted the temperature every second hour with a thermometer suspended to a post on the ice. Mr. Dodge undertook for me a set of ice measurements, and the telescope was mounted alongside the vessel, in a dome made with blocks of ice and snow. [Footnote 3: These instruments were carefully compared at every ten degrees of temperature down to -40°, and the records were subsequently referred to our "standard," a fine instrument which I had from G. Tagliabue.]