134 



NA TURE 



\Pec. 17, 1874 



REAPPEARANCE OF ENCKES COMET 

 TT is quite possible that before the close of the next 

 A period of absence of moonlight in the early evening 

 hours, the comet of Encke may be again detected with 

 the large telescopes now to be found in our observatories. 

 The mean motion determined by Glasenapp for the last 

 perihelion passage at the end of December 1871 would 

 bring the comet to the same point of its orbit about 1S75, 

 April 1 1.5, which was very nearly the date of passage 

 through perihehon in 1S42. When it was last m aphe- 

 lion, in the middle of August 1S73, I find its distance 

 from the planet Jupiter would be 10-02, and that from 

 Saturn 7-3, so that the perturbations during the present 

 revolution are likely to be small; the comet still ap- 

 proaches near the orbit of Mercury in heliocentric longi- 

 tude 1237° and latitude 6-8' N., but it has not encoun- 

 tered that planet since November 1S48. Assuming, then, 

 that the least distance from the sun will be attained at 

 midnight on the nth of April next, we have the following 

 positions of the comet during the period I have named : — 

 At 1211. Greenwich Time 



Distance Distance 

 t.P.D. fj.jj^ Earth, from Sun. 



I '945 



1-976 

 1-981 



1-919 

 1-S74 

 1-S28 

 I -781 

 1-733 



88 19-9 

 88 9-9 



87 57-2 

 87 41-6 

 87 23-2 

 An acceleration or retardation of four days in the time 

 of perihelion passage will not change the geocentric place 

 more than fifteen minutes of arc, so that if the comet be 

 within reach it may be easily found. 



It will be interesting to learn what account some of 

 the large reflecting telescopes with which many amateurs 

 in this country have provided themselves, can give of the 

 comet at this return. 



The computation of the perturbations and preparation 

 of an accurate ephemeris for 1875 is understood to be in 

 the hands of Dr. von Asten, of Pulkova ; but I am not 

 aware that the results have yet been given to astronomers. 



J. R. Hind 

 Mr. Bishop's Observatory, Twickenham, Dec. 14 



NOTES 



Since our last week's note, we undeista'nd that the whaling 

 steamer Bloodhound, of Greenock, has been purchased as the chief 

 vessel of the new Arctic Expedition. Other whalers have been 

 examined by .Sir Leopold M'Clintock, but none have been 

 deemed suitable. The Bloodhound is a screw steamer, whose 

 engines are nominally 96 horse-power ; she is barque-rigged, two 

 years old, strong, sound, and well appointed, and handy either 

 imder steam or canvas. It is announced that the vessel chosen 

 to be the consort of the steam-whaler Bloodhound in the forth- 

 coming expedition is Her Majesty's ship Alerl. She is a five-gun 

 steam-sloop of 751 tons old measurement, and 100 horse-power 

 nominal. The Alert has been docked at Portsmouth and will 

 undergo a thorough survey. Active preparations for the equipment 

 of the ships will soon commence, but the start will not be made 

 until the latter part of June of next year, as it is considered merely 

 waste of labour and time to push across the north water until the 

 ice has had time to melt and drift out from Smith's Sound. A 

 request has been made by the Foreign Office that the Danish 

 Government will peiTnit their agents at Disco, Proven, and 

 Upeniavik to collect hunters, dogs, anddog-drivers for the Arctic 

 Expedition. Capt. Nares is expected to arrive in this country 

 about the end of January, 1875. The Committee for making 

 arrangements with respect to the Expedition sat on Tuesday 

 and -Wednesday at the Admiralty for the purpose of deciding 

 on the provisions and clothing to be supplied to the members of 



the expedition. They havejbeen occupied hitherto with details 

 as to the route. 



Apropos of the possible biological results of the Arctic Expe- 

 dition, we may recall to recollection a few additional details to 

 those given last week of what was accomplished by the Polaris. 

 The northern limit actually reached was 82° 16'. Yet at this 

 extreme latitude fifteen species of plants were collected, five of 

 which were grasses. Twenty^six musk oxen were shot in lat. 

 81° 38'. Dr. Bessels also made a fair collection of insects, 

 principally flies and beetles, two or three butterflies and raos- 

 quitos ; and birds of seventeen different kinds were shot in 82°, 

 including two Sabine gulls and an Iceland snipe. 



During the whole of the past week the members of the 

 French Academy of Sciences have had frequent meetings to 

 receive the telegrams from the several French Transit stations. 

 The first, from Janssen, relieved them of a great anxiety, and 

 was published instantly. The most extraordinary measures 

 have been taken to secure the safe transmission of the results of 

 the observations at French stations. The chief of each station is 

 ordered to make four copies of his observations. One is 

 to be left under a cairn, or a tree (if any in the country), 

 or m an excavation, the site to be described in a letter to the 

 Institute ; the second is to be handed over to the captain of 

 the first French ship that is met, with instructions to bring it 

 himself to the Institute ; the third is to be delivered to the 

 nearest French consul, agent, or ambassador ; the fourth is to be 

 kept by the chief of the station himself 



MM. FiZEAU and Comu, authorised by M. Leverrier, have 

 been making an experiment of the highest importance at the 

 Paris Observatory, the results of which were to be given at Mon- 

 day's sitting of the Academy. The two savants Inve been 

 measuring the velocity of transmission of light, by experiments 

 carried on between the Observatory and Montlhery. The light 

 sent to Montlhery is reflected and returns to the Observatory, 

 the distance there and back being 22,000 yards. The experiment 

 has never hitherto been made on so grand a scale, nor with 

 such precautions ; ten powerful instruments were used. 



Her Majesty's ship Basilisk, which has just returned to 

 England after a commission of nearly four years, has (the Times 

 states) surveyed about 1,200 miles of coast line, added at least 

 twelve first-class harbours, several navigable rivers, and more 

 than one hundred islands, large and small, to the chart ; and, 

 lastly, has been able to announce the existence of a new and 

 shorter route between Australia and China. Till these Basilisk 

 discoveries were made, a large archipelago of islands (some as 

 large as the Isle of Wight, and densely populated), a rich fertile 

 country, intersected by navigable rivers, and inhabited by a semi- 

 civilised Malay race, remained unknown to us. After the news 

 of this ship's first discoveries reached England, Lieut. Dawson, 

 R.N. (Admiralty Surveyor), was sent out to join her, and she 

 was ordered to complete and follow them up. This has been 

 done with perfect success, and the whole of the previously 

 unknown shores of Eastern New Guinea have been carefully 

 surveyed, and the route above referred to opened up. The 

 principal part of this work of discovery and surveying has been 

 performed by the captain and officers in small open boats, de- 

 tached from the ship in some instances for many weeks, and 

 among savages who had never before seen a white face. It 

 is stated that two lofty mountains, about 11,000 feet high, 

 facing each other on the north-east coast of New Guinea, have 

 been named " Mount Gladstone" and "Mount Disraeli." This 

 intelligence will have an interest of rather a tantalising kind for 

 naturalists. There is hardly any part of the world more pro- 

 mising to students of the geographicaldistribution of living forms 

 than that which the Basilisk has sui-veyed. Collections, more 

 especially of the plants, might doubtless often have been made. 



