312 



NA. rURE 



{Aug. 19, 1875 



accuracy, but having three, ihe rtadiugs of ihem cannot be ques- 

 tioned by the most sceptical. 



We left Sandy Hook on the forenoon of April 10, with a light 

 north-west wind and pleasant weather. Temperature of the air 

 46, barometer 29-82. From that date to the i6th the ship 

 steamed 2,210 miles, and the mercury, with the exception of a 

 slight fluctuation which never exceeded ^f^ of an inch, fell 

 steadily until it reached 29-14 on the latter day. Throughout 

 this period the wind veered and backed between N.N. W. and 

 E.N. E., never exceeding in force a whole sail breeze, and fre- 

 quently light or calm for hours together. The sky was generally 

 overcast until the meridian of 32° W. was passed ; light rain 

 fell once, but no snow or sleet. Temperature of the air ranging 

 between 34° and 57°. 



Until the .ship was to the eastward of Cape Race (passing 300 

 miles south of it), as no gale blew I expected a heavy fall of 

 snow ; but as it did not come, I assumed that the snow-covered 

 ice on the Grand Bank of Newfoundland caused this unusual 

 depression of the mercury. Great was my surprise, therefore, 

 to see it falling lower as the distance increased from the supposed 

 cause of the depression, while the wind gradually died away, the 

 clouds opened out and assumed softer forms, the horizon cleared, 

 and the long northerly swell subsided. The latter is always a 

 sign of fair weather on this troubled sea. If a storm be advan- 

 cing towards a ship, the swell usually comes before the wind, so 

 quickly is the motion of the water translated. 



While on the subject of waves, I may state that I have been 

 investigating the cause of the greater height of the waves raised 

 by a north-west wind above those raised by a south wind. The 

 observations were made while crossing several offshoots of the 

 Gulf Stream, and I found that in every instance the sea was 

 smoother in the warm water than in the cold. If this view be 

 correct, then the waves in tropical seas should be inferior in 

 height to those of the temperate zone. The question is, Are 

 they so? 



Snow has an extraordinary effect on the barometer, but its 

 action is most mysterious, as in this case the ship was several 

 hundred miles from any locality where snow could have fallen. 



In March 1872 I witnessed a similar instance of great depres- 

 sion in the barometer, with no wind and a clear sky. On reach- 

 ing the land it was found to be covered with snow. In that 

 instance there was scarcely a cloud visible during the last 400 

 miles, and not a single flake fell on the ship. I believe the 

 remarks of an old seaman on the weather of the Atlantic are 

 very true, viz., "The longer one sails on it the less one knows 

 about it." 



The presence of heavy field-ice in the month of April, so far 

 south as 4i°4o'N., only fifty miles north of the latitude of 

 Naples, has excited considerable astonishment amongst Atlantic 

 navigators, since many steamers were entangled in it as early as 

 the 24th of January. 



The Admiralty Chart of 1873 indicates March as the first 

 month of its arrival, and further gives lat. 42° 13' N. as the 

 extreme southern limit of its existence, whereas it has already 

 been met with twenty-seven miles south of that parallel, forming 

 a dangerous barrier to ships on the great highway to America : 

 and the commanders of those vessels, relying implicitly on the 

 correctness of a survey which should be above suspicion, have 

 seriously injured their vessels, thereby jeopardising many lives 

 and valuable property in a locality where every feature of it 

 should be as well known as the waters of the Serpentine or 

 the Thames above bridge. It is, moreover, notorious that this 

 is not the only defect in the chart of 1873. The northern limit 

 of the Gulf Stream is laid down from 100 to 150 miles south of 

 its true position ; and the existence of another important current 

 (the Labrador), which plays no mean part in the economy of 

 the globe, is entirely ignored, although its line of demarcation 

 from the adjacent waters is as well defined as that of its great 

 neighbour. 



It is stated by the old residents of Canada that such a severe 

 winter as this has not occurred in the Dominion for forty years. 

 During the months of January and February at Montreal the 

 wind only blew from the south for six hours. Not only was the 

 thermometer low, but the northerly gales were incessant, render- 

 ing outdoor exercise almost an impossibility. These storms 

 broke the ice of Newfoundland and Labrador from its moorings 

 before the summer sun could soften it, and hence the reason of 

 its floating down south. Being almost as hard as granite, and 

 with the sea water at 30°, it will not readily decompose. 



The recent severe wmter must affect the fortunes of the polar 

 ejcpedition for good or for evil. Channels into which ice has 



drifted will become inaccessible until late in the season, but, on 

 the other hand, the pack-ice will be less inconvenient from its 

 solidity and compactness. It is not probable that many large 

 bergs will reach the Atlantic this season. 



Cdlic W. W. Kiddle, R.N. 



The late W. J. Henwood, F.R.S. 



Mr. G. T, Bettany is no doubt very nearly, if not quite, 

 correct in saying of Mr. Henwood (Nature, vol. xii. p. 293), 

 " I believe that scarcely one of his cherished objects in this 

 respect [the arrangement of his stores of facts and observations] 

 remains unfulfilled." 



In a letter to me, dated July 31, 1875, Mr. Henwood re- 

 marked : " I believe all I have done since [I wrote you last] has 

 been to make some preliminary calculations regarding the correc- 

 tions for temperature of the results of my observations on mag- 

 netic intensity, made on the surface and near the bottom of 

 Dolcoath Mine in 1832. I think they hold out promise of some- 

 thing if I have only strength to put them in order." On the 

 fifth day after writing this* he died. M. Y. 



Zoology of the "Erebus" and "Terror" 

 Palmani qui meruit ferat. Referring to the article on this 

 subject (Nature, vol. xii. p. 289), allow us, as the publishers 

 of the botanical portion, to say that the indefatigable labours of 

 Dr. Hooker, aided by the Government grant, resulted in six 

 vols. 4to. ; not two, as stated by the reviewer. This was pub- 

 lished in three divisions, viz. : i. Flora Antarctica, 2 vols. ; 2. 

 Flora Nov£e Zealandse, 2 vols. ; 3. Flora Tasmaniii;, 2 vols. ; 

 the whole comprising nearly 600 coloured plates. 



L. Reeve and Co. 

 5, Henrietta Street, Covent Garden, Aug. 14 



The Rocks at Ilfracombe 



Could any of your readers state in your columns the nature 

 of a curious appearance in the rock near Ilfracombe (North 

 Devon), on the way to Coombe Martin, just where the road 

 begins to descend to the latter place ? Here on the right-hand 

 side the bank is considerably excavated, and through the scaly 

 and friable strata, whose cut surface is perpendicular to the road, 

 rock of a harder kind seems to have been pushed, presenting a 

 rounded surface, which gives the appearance of trees laid in the 

 bank and partly uncovered ; indeed, I first heard of them as 

 " petrified trees," and from the road they look very much like 

 the trunks of silver birches. Our Ilfracombe driver told me that 

 a great many people came to look at them, some saying they 

 were trees, others that they were not. 



There are several of them, and various lengths are visible, from 

 about a yard to twenty feet, I should think. 



William S. Tuke 



OUR ASTRONOMICAL COLUMN 

 Binary Stars.— (i) 77 Cassiope^. — Dr. Duner, of the 

 Observatory of Lund, Sweden, has calculated elements of 

 this binary from measures 1782-1874 ; the orbit is as 

 follows : — 



Peri-astron passage, I748"4i3 



Angle between the lines of nodes and apsides 245° -91 1 ATpv-ijion 

 Node . . . . 50 '83 > ^f ,e^^ 

 ■r Inclination . . 68 -46 j °^ '^^o 

 Angle of excentricity (= sin-' ^) 38 •812 

 Mean annual motion . . . . -}- 2 •04112 



Semi- axis major io"'68i 



Period of revolution . . . 176*374 years. 

 The comparison with measures used by Dr. Duner in his 

 calculation shows very small residual errors, but the 

 elements here transferred from Leverrier's " Bulletin 

 International" of the 12th inst., though representing the 

 angles of Struve, Dawes, Jacobs, and Dembowski, with 

 small negative errors give the distances measured since 

 1827, very sensibly in defect of the observations. Thus 

 for Dembowski's measures we have — 

 1863-26 Error in position - o°'72 Error in distance — o"-69 

 1867-16 ,, ,, - o -71 ,, „ -o -63 



1871-05 ,, ,, - o -18 ,, ,, -o -46 



For a normal founded upon measures by Jacobs, 

 Dawes, and Dembowski, for 1854*20, the error in position 



