232 



NATURE 



{July 13, 1876 



small star from Venus, 10 minutes 20 seconds. Venus 

 then appeared very distinctly, and the sky being very 

 clear, he took eyepieces three or four times more power- 

 ful, and saw, with an agreeable surprise, that the small 

 star showed a phase, and the same phase as Venus ; its 

 diameter was rather less than a third of that of Venus, 

 its light not so vivid but well defined ; the great circle 

 which passed through the centres of Venus and of the 

 satellite, which it would be difficult to designate otherwise, 

 made an angle of about 18 to 20 degrees with the equator, 

 the satelHte being a little towards the north, and preced- 

 ing Venus in right ascension. Mr. Short examined it at 

 different times and with different telescopes during the 

 space of an hour, until the light of day or of the twilight 

 obliterated it entirely." 



It will be seen that Short's observation, divested of the 

 typographical error in the Phil. Trans., by which it was 

 confused, is intelligible enough, and it may not be without 

 interest if we examine the circumstances under which it 

 must have been made. 



Taking the place of Venus with sufficient precision for 

 the purpose in view from the tables of Le Verrier, we have 

 the following figures : — It may be premised that the date 

 given in Nature last week from the Phil. Trans, is the 

 morning of October 23, but it is to be remembered that 

 the Gregorian style had not then been introduced in this 

 country ; in the present mode of reckoning, it becomes 

 the morning of November 3, as slated in the " Histoire de 

 I'Academie." 



Venus, App. Dist. of Venus 



^ G.M.T. App. R.A. N.P.D. from the Earth. 



1740, Nov. 2, at i8i» 30™ 175° 21' 11" 87° 12' 21" 07007. 

 Hourly motion in R.A. + 2' 28" ; in N.P.D + o' 49". 



The apparent diameter of Venus (Le Verrier) was 23"7, 

 and her heliocentric longitude being 86° 11', and her geo- 

 centric longitude 174° 38'; the breadth of the illuminated 

 portion of her disc was 0*514 ; elongation, W. 46^°. 



Short says the daylight put a stop to his observations 

 " about a quarter of an hour after eight," which we may 

 assume to imply apparent time, and as the correction 

 from apparent to mean time was then i6™'i subtractive, 

 his observation may be supposed to have terminated at 

 8 A M., and as he had viewed the object during the space 

 of an hour, we find Venus must have been at an altitude 

 of 36" when he first perceived it, and further, it should be 

 noted, the sun rose at i^ o™, so that Short's observations 

 must have been made entirely in daylight, with the planet 

 particularly well situated. 



The suspected satellite was i8''-20° north-preceding 

 Venus, which implies a mean angle of position of 289°, 

 and as the distance was 10' 20", we have for the difference 

 of right ascension, 39^"i, and for the difference of N.P.D., 

 3' 22". Supposing these differences to apply to 7'' 30"^ A.M., 

 the position of the object would be R.A. 1 1'' 40'" So^'6, 

 N.P.D. 87° 9' 23"; whence, bringing forward to the epoch 

 oi ih.Q Durchmustening, its R.A. is 11'' 46™ 46% N.P.D. 

 87* 47'-5 for 1855-0. 



Unless we had been able to correct the misprint in the 

 Phil. Trans, by the French account of the observation, 

 it might, perhaps, have been inferred that the distance 

 was intended to be i" 2' or 1° 12', and in this case the 

 3.4 magnitude star jS Virginia would have fallen very 

 nearly upon Short's position ; at 7 A.M. this star preceded 

 Venus 1° 5', and was N. 26'. 



It will be found that our examination of Short's obser- 

 vation does not tend to explain it. Though Lalande 

 thought when conversing with him on the subject in 1 763, 

 that he doubted his having observed a satellite of Venus, 

 he appears to have been sufficiently impressed with his 

 observation to have had the appearance engraved, and to 

 have " carried it with him as a seal." 



The observation of Andreas Mayer at Greifswald, 

 mentioned in Nature last week in the notice of Schorr's 

 " Der Venusmond," was communicated to Lambert after 



the appearance of his memoir " Essai d'une thdorie du 

 satellite de Vdnus," in the Berlin Memoirs, 1773, of which 

 an abstract is found in the Astronotnisches Jahrbnch, 

 1777. It is printed at p. 186 of the Jahrbuch for 1778, 

 where also appear the two letters from Abraham Scheu- 

 ten to Lambert, referring to his observations of what 

 he believed to be a satellite of Venus, after the planet 

 had left the sun's disc in the transit of 1761, June 6, 

 which at noon at Crefeld was near the centre of the 

 disc and at 3 p.m., near the limb. Lambert follows with 

 a particular examination of Scheuten's observation in 

 connection with the observations of Montaigne at Li- 

 moges in May preceding. 



y Argus. — Gilliss, in the notes to the 1850 " Catalogue 

 of Double Stars observed at Santiago," remarks of this 

 object : " The cluster deserves special attention for its 

 evident changes since Herschel's observations." From 

 a comparison of the observations it is not obvious to 

 what changes reference is here made. Perhaps some 

 reader of Nature who can favourably command this 

 star's position will describe the actual configuration, &c., 

 of the principal star and vicince. 



Mr. S. M. Drach writes with reference to views of 

 binary stars from Venus and Mars : " Has it ever been 

 noticed by cosmographists tkat an observer at these 

 planets must see our moon at a maximum elongation- 

 angle from our earth, ranging from Venus from StS: to 315- 

 minutes of degree, and from Mars from 3 J to 16^ minutes 

 of degree, whence follows that o\xx present century's certi- 

 tude of Binary Stellar Systems is a primitive feature of 

 naked-eye astronomy to the Venus or Mars observers. 

 This elongation diminishes to zero in about seven days 

 of either planet, since their rotation periods nearly equal 

 the earth's." 



THE NORWEGIAN-ATLANTIC EXPEDITION 



THIS Expedition left Bergen June i for the Sognefiord, 

 where the first week was spent in preparatory work — 

 sounding, dredging, and trawling in 600 fathoms. The 

 temperature at the bottom was found exactly the same as 

 in former years, 43°7 F. The fauna was a mixture of 

 Atlantic and Arctic. There were found several specimens 

 oi Brisinga coronata {^vc%), Munida tenuitnana, one large 

 Actinia and a sponge, Tisiphonia as^ariciformis., and, 

 among other moUusca, Aximus etintyarius (Sars), Kel- 

 liella abyssicola (Sars), Malletia obtusa, and Taranis 

 Aiorchi. The second week was spent at Hiiso, a small 

 island at the mouth of the Sognefiord, where magnetical 

 base-observations were made on shore and on board, ship 

 swung for deviation, &c. 



June 20 the Expedition left this place, and steered 

 along the deep channel surrounding Southern Norway 

 from the Skagerrack up to Cape Stadt. The first sound- 

 ings and dredgings showed a very flat bottom at a depth 

 of about 200 fathoms, and with a fauna mainly Atlantic. 

 About 150 miles N.W. of Cape Stadt the temperature 

 began to fall, the depth remaining unchanged. At the 

 next sounding the depth increased and the bottom tempera- 

 ture was still falling, until at last the Miller- Casella ther- 

 mometer showed 32° at 300 fathoms, and 30° at the bottom 

 in 400 fathoms. This is exactly like what the Porcupine 

 found in the Lightning Channel. Off Stadt the fauna 

 was Arctic and Glacial. Among the specimens brought 

 up was a gigantic Umbelhilaria, 5 feet high, a Nymphon, 

 10 inches between the ends of the feet, a new large 

 Archaster, and many other characteristic forms. No less 

 than eight forms of Hydroids were also found at this 

 depth, three different species of Arctic Fusus, and several 

 specimens of Yoldia intermedia, &c. 



The Expedition ran into Christiansund June 23, and 

 was to leave that port in a feiv days for the Faroes and 

 Iceland. 



