74 FARTHEST NORTH 



nation, and intensity (both horizontal and total intensity) 

 we had a complete set of instruments. Among others 

 may be mentioned a spectroscope especially adapted for 

 the northern lights, an electroscope for determining the 

 amount of electricity in the air, photographic apparatus- 

 es, of which we had seven, large and small, and a photo- 

 graphometer for making charts. I considered a pendu- 

 lum apparatus with its adjuncts to be of special impor- 

 tance to enable us to make pendulum experiments in the 

 far north. To do this, however, land was necessary, and, 

 as we did not find any, this instrument unfortunately did 

 not come into use. For hydrographic observations we 

 took a full equipment of water-samplers, deep-water ther- 

 mometers, etc. To ascertain the saltness of the water, we 

 had, in addition to the ordinary areometers, an electric 

 apparatus specially constructed by Mr. Thornbe. Alto- 

 gether, our scientific equipment was especially excellent, 

 thanks in great measure to the obliging assistance ren- 

 dered me by many men of science. I would take this 

 opportunity of tendering my special thanks to Professor 

 Mohn, who, besides seeing to the meteorolof^ical instru- 

 ments, helped me in many other wa3^s with his valuable 

 advice ; to Professor Geelmuyden, who undertook the 

 supervision of the astronomical instruments ; to Dr. Neu- 

 meyer, of Hamburg, who took charge of the magnetic 

 equipment ; and to Professor Otto Petterson, of Stock- 

 holm, and Mr. Thornoe, of Christiania, both of whom 

 superintended the hydrographic department. Of no less 



