SCIENCE.-SuPPLEMENT. 



FRIDAY. MARCH 4, 1887. 



THE MAGNETIC AND TIDAL WORK OF 

 THE GREELY ARCTIC EXPEDITION. 



It is well known that the expedition sent out 

 by the government to Lady Franklin Bay in com- 

 mand of Lieut. A. W. Greely, U.S.A., was one of 

 two expeditions to co-operate with and form part 

 of the physical explorations proposed by the Inter- 

 national polar commission. By invitation of its 

 president the late General Hazen, chief signal 

 officer, accepted the organization and fitting-out 

 of two parties, one, under Lieutenant Greely, to 

 proceed to the shores of Lady Franklin Bay, Grin- 

 nell Land, the other, under Lieut. P. H. Ray, to 

 go to Uglaamie, Point Barrow, Alaska. While the 

 general responsibility, the supervision, the ac- 

 counts, the selection of men, and their transpor- 

 tation to and from the stations, remained in his 

 own hands. General Hazen requested and received 

 the aid of the coast and geodetic survey in the 

 special departments of terrestrial magnetism, of 

 tides, and gravitation. The assistance of the sur- 

 vey by its then superintendent, Capt. C. P. Patter- 

 son, consisted in furnishing such instruments as 

 could be spared from its limited supply, in train- 

 ing the observers for their work, and in providing 

 them with the necessary instructions and forms 

 of record for the proper performance of their duty. 

 It so happened that congress had already (in 1880) 

 authorized a scientific expedition to Lady Franklin 

 Bay, but the funds were appropriated so late in the 

 spring of 1881 that it was found impossible to pro- 

 cure the needed special instruments and to give 

 that thorough training to the corps of observers 

 which could only be attained by ample time 

 for preparation. Indeed, the commission itself 

 found it expedient to start other expeditions a year 

 later, in order to obtain better organization of the 

 scientific labor, and especially for the construction 

 of suitable magnetic differential instruments. 



There is no need of referring here to the general 

 history of the two American expeditions, as we 

 already possess the official publication of the one 

 under Lieutenant Ray, and the narrative of the 

 Lady Franklin Bay party, in two handsome 

 volumes, by its leader. Lieutenant Greely. By his 

 permission we are enabled to lay before the read- 

 ers of Science the general results of his labors 

 during 1881-84 in the domains of terrestrial mag- 

 netism and of tides. They are extracted from the 



manuscript now ready for the printer, but it is not 

 our intention to enter minutely into any details, 

 which would be here out of place, nor to fore- 

 stall the judgment of scientists on the merits 

 of the work : this must be reserved for a time 

 after the official publication and when the results 

 by the several international expeditions can be com- 

 pared and collated. A brief statement of facts so 

 far as they relate to that part of the work which was 

 intrusted to the special direction of the U.S. coast 

 and geodetic survey, is all we propose to give at 

 present. 



The astronomical and magnetic work of the ex- 

 pedition was placed in special charge of Sergeant 

 Edward Israel, who unfortunately was one of 

 tho?e not permitted to return, but whose records 

 abundantly testify to his faithfulness and pains- 

 taking industry. Copies of these records in a 

 highly condensed form were safely brought home, 

 and were placed in the hands of C. A. Schott, as- 

 sistant, coast and geodetic survey, for discussion 

 and for preparation for the press. This task was 

 rendered somewhat difficult from want of addi- 

 tional explanation on the part of the observer : 

 fortunately Lieutenant Greely took the precau- 

 tion, when retreating from his station in 1883, to 

 bring with him the magnets and pendulum, thus 

 permitting certain supplementary observations to 

 be made at home. This cannot be too highly com- 

 mended, when we consider that every pound of 

 dead weight carried necessitated leaving behind 

 so much food to sustain the life of the party on 

 their perilous retreat. In jvidging of the merits 

 of the labors of the expedition, it should be borne 

 in mind that all efforts had failed to succor this 

 party, which occupied the northernmost station 

 assigned to any of the expeditions, and that, at 

 the time of its sailing, certain magnetic instru- 

 ments needed for fully carrying out the pro- 

 gramme adopted by the international commission 

 could not be obtained. 



The magnetic observatory at Fort Conger was 

 erected a short distance from the main house, and 

 was supplied with a new magnetometer made by 

 Fauth & Co. of Washington, and with a dip circle 

 of the Kew pattern, but it had no differential in- 

 struments. The observations were made on Got- 

 tingen mean time, which differs 4^^ 59"^ from local 

 time and b^ 48"" from Washington time. A small 

 transit, loaned by the survey, served for the de- 

 terminations of time and longitude. The observa- 

 tions for time and latitude were made by means 



