272 



NA TURE 



\_Aiigust 2, 1877 



tions on shore were secured by Capt. Wille. The neces- 

 sary observations for compass error having been obtained, 

 the Vdrhiiji'H returned to Bergen, where the scientific staff 

 was assenibled. There was, however, something still 

 wanting before we could put to sea. The accumulators 

 used last yenr had got britde, and new ones had been 

 ordered from London in March, but they had not arrived 

 in May, and in answer to a telegram Capt. Wille learnt 

 that the order had been forj;otten. The new accumulators 

 kept us v/aiting in Bergen till June 1 1, when we sailed for 

 Stavanger, and received them on the 13th, and we put to 

 sea at once. 



Outside the coast we took a series of temperatures, 

 which showed the minimum, not at bottom, but at a 

 certain depth below the surface. The same phenomenon 

 has lately been observed in all latitudes near the coast. 

 I attribute it to the action of the winter cold on the sea. 



Our first working station was m iat. 66° 8''5, long. 3° o' 

 E., which was reached on the morning of June 16. The 

 depth here was 805 fathoms, the temperature at bottom, 

 29°7. We now worked in even sections, running west- 

 noith-west and east-south-east perpendicular to the coast. 

 The third section from Iat. 67° 53', long. 5° 12' E. to the 

 island of Trocuew having been completed, we went 

 northwards into the West Fiord, where a series of tem- 

 peratures was taken with Negretti and Zambra's deep-sea 

 thermometer. Last year we could not use this instrument 

 at sea because the slightest upward movement of the 

 ship caused the thermometer to turn over before it 

 had had sufficient time to accommodate itself to the 

 temperature of the sea. This year it was fitted with 

 a new turning apparatus devised by Capt. Wille, which 

 proved satisfactory. In the outer part of the West Fiord 

 the temperature on the surface was 45°7 ; it decreased to 

 38^'8 in sixty fathoms ; and from that point it rose to 41° o 

 in 140 fathoms, ten fathoms above the bottom. The 

 Casella- Miller thermometer of course registered from this 

 depth the minimum 38°'8. The phenomenon here noticed 

 is universal all along our coasts in the summer months ; 

 I discovered it for the first time in the West Fiord two 

 years ago. The explination seems to be this : In winter 

 the air is generally cooler than the sea-surface, especially at 

 the coast ; the water is chilled from above, an-d the cooled 

 layers being denser, sink down, and so the winter cold de- 

 scends in the water ; the temperature down to a certain depth 

 mcreases with the depth. When spring and summer 

 come, ihe air warms up the sea surface, and the surface 

 layers getting warmer get lighter also, and have no 

 tendency to sink. The temperature becomes highest at 

 the sui face, and decreases to a certain depth, below which 

 the action of the winter cold still shows itself in a 

 temperature increasing with the depth. 



After dr, dging and trawling in the inner part of the 

 West Fjord, we went to Boeld, where the expedition 

 stayed a couple of days. On the 26th we arrived at 

 Rosh, the outermost of the LolToden Islands ; there we 

 stayed some days, strengthening the accumulators, 

 cleaning the ship, taking magnetical and astronomical 

 observations, and making excursions. 



We left Rcish on the 2Sth at noon, and commenced our 

 work on the sections further north, sounded, dredged, and 

 trawled outside the Loffoden Islands till the 30th, when 

 we went into the Hadsel Fjord, and anchored at 

 Sortland in Westeraalen. The next week was spent in 

 working outside Westeraalen. There the greatest depth 

 for this year was reached, 1,710 fathoms in Iat. 

 70", long. 6° 15' E. The Casella-Miller thermometer 

 registered at the bottom a temperature of 28^4 when 

 corrected for instrumental error and for pressure, the 

 lowest temperature hitherto found by our expedition. A 

 series of temperature observations showed that the tem- 

 perature at all depths decreased with the depth, and that 

 32° lay in about 580 fathoms. The next Sunday, July 8, 

 found us in Tromsd. 



The expedition has this summer been favoured with 

 remarkably fine and quiet weather, which has allowed us 

 to carry out all our operations according to our proposed 

 plan. The number of sounding stations is already loi ; 

 last year's total was only 93. Seventeen serial tem- 

 peratures have been obtained, and the dredjie and trawl 

 have been out on the bank in the Umbcllularia region 

 (one specimen has been caught), and in the deep 

 bihculiim clay, at the depth of 1,700 fathoms, animal life 

 was rather scarce. The boundary line between the water 

 above and below 32° at the bottom, lies between Iat. 65" 

 and the Arctic circle as far west as 5° 30' E. A 

 little north of the Arctic circle it has a curvature 

 towards the coast, and farther north it lies only 

 from five to ten geographical miles off the outer 

 side of the islands of Loffoden and Westeraalen. On 

 this northern part the edge of the bank is very steep, ard 

 the bottom falls very rapidly towards the deep part of the 

 Arctic Ocean. Out at sea the isothermal surface of 

 32" lies at very different depths in different latitudes. In 

 the channel between Faroe and Shetland, it lies in 300 

 fathoms, between Iceland and Norway it sinks to 400 

 fathoms, and between Jem Mengen and Norway we have 

 found it in 580 fathoms. To the westward it rises, as we 

 found last year, cast of Iceland. How it behaves further 

 north, off Spitzbergen, we expect to find next year. Near 

 the coast, 32° always lies at a much higher level. 



The Umbcllularia region has been found extending as 

 far down as 880 fathoms off Westeraalen, where the 

 specimen found came up with the weights on the dredge 

 rope. In several places oft" the coast we have found, 

 besides Norwegian rocks, specimens of chalk and flint. 

 Of deep-sea animals, some new species have been found. 

 On the bank off Langenes (Iat. 69^) we caught plenty of 

 the same kind of fish as are caught at the bank fisheries 

 on the " Storeggen," off the coast of Romsdal. 



The expedition is now lying at Tromsd, refitting and 

 taking in stores for further work. We intend first to work 

 only two more sections north of Tromsd, and then call 

 here to make all ready for the voyage to Jem Mengen. 

 From that island the course will be westward till we 

 reach ice-cold water, then southwards to a point midway 

 between Jem Mengen and Iceland, and thence to Bodd, 

 whence the expedition will return to Bergen. 



Among the novelties used in our work this year I must 

 mention a piezometer, kindly sent me by Mr. Buchanan, 

 chemist of the Challenger. This instrument has regis- 

 tered the depth very well. A new atmoineter of my own 

 construction has been constantly in use, giving good 

 results. Two such instruments have, under favourable 

 circumstances (they cannot be used m rough weather), 

 given almost identical results ; the depth of sea-water 

 evaporated in twenty-four hours is sometimes more 

 than four millimetres. Meteorological observations have 

 been made every hour when at sea. The chemist has got 

 many samples of air from the sea-water, both at the 

 surface and at the bottom. He has taken the specific 

 gravity of the water and determined its amount of 

 chlorine. He has also made several determinations of 

 its amount of carbonic acid. 



MR. FROUDE'S NEW DYNAMOMETER 

 ]\/[ R. FROUDE, in solving the problem assigned to him by 

 ■'■'-'■ the Admiralty — of producing a dynamometer calculated to 

 test the power delivered at the end of the screw-shaft by large- 

 sized marine engines — has enabled us to utilise a new principle 

 of great value among the "applications of science." 



In the friction-brake dynamometer, as is well known, the power 

 delivered to a revolving shaft is measured by the rate at which a 

 definite weight is being virtually lifted, and the number of foot- 

 pounds of work done per minute is the circumference of the drum 

 at the effective radius at which the weight is lifted, multiplied by 

 the weight and by the number cf revolutions per minute. Simple 

 as the arrangement is when employed on a small scale, it 



