SCIENCE-GOSSIP 



59 



greatesl eclipse, as seen fr Dalston, the sky was 



very cloudy, bul away to the south-east a patch of 

 blue sky was visible, Looking dark and dull, more 

 like thai of winter than a1 the end of .May. Some 

 observers had an interesting sighl where the sun 

 shone between the leaves of a tree and formed on 

 the ground a multitude of little crescents of Light. 

 No trace of the moon appears to have been visible 

 projected on the corona. During the eclipse, 

 Professor Howe, of Denver Observatory, Colorado, 

 succeeded in obtaining a photograph of the plani i 

 Eros. 



CONDUCTED BY I'. SHILLINGTOS SCALES, I'.I.'.M. 



CHAPTEKS FOE YOUNG ASTRONOMERS. 



B> l'i. ISK C. 1 >i:vn i .-[- 1 . 



VENUS. 

 [Continued from pag 27.) 



Twice J. D. Cassini thought In- observed a satellite 

 to Venus: on January 25th, 1672, and on August 

 28th, L686. James Short, the celebrated optician, 

 made a similar observation on October 23rd, 1740. 

 Montaigne on three nights in May, 1761, also 

 thought he observed the satellite ; and Baudouin 

 calculated its orbit. Mayer in 1759, also Rodkier, 

 Horrebow, and three others at Copenhagen, and 

 Montbarron at Auxerre, in March. 1764, are all said 

 to have made similar observations. A Belgian astro- 

 nomer, Stroobant, has been at great pains to show 

 that most of the observers had really seen stars 

 which he identifies ; his work, however, is fruitless, 

 as the object observed always had a diameter from 

 a quarter to one-third of that of Venus, and more- 

 over had a phase similar to that of the planet. 

 The true explanation is doubtless a "ghost" in the 

 telescope, one cannot say eyepiece, for Short used 

 three or four eyepieces. Seeing that the majority 

 of these observers were well experienced, their 

 mistakes should act as a caution to those who are 

 a- yet only beginners in the science. If any 

 abnormal appearance i> observed, it is well to give 

 the eyepiece a quarter turn, or even to changethe 

 eyepiece. This will frequently expose or exorcise 

 the '• ghosts." If possible, it is also well to appeal 

 to another telescope. 



^ One of the most ancient recorded observations of 

 Venus is that by Timocharis, who witnessed the 

 apparent occupation of a star at the extremity of 

 Virgo's wing, on a date corresponding, according 

 to Hind, with October 12th. 271 B.C. Similar 

 occultations of aLeoni.-. Kegulus, are mentioned by 

 Maestlin on September Kith. 157-4, and Kepler on 

 September 25th, 1598. .Mars also suffered occulta- 

 tion in 1590 on October 3rd, and that of Mercury 

 occurred on May 17th. 17:57. 



_ One striking fact concerning Venus is that the 

 limb, or edge of the disc. i> always the brightest 

 part of the planet. 



From time to time wonderful stories are circu- 

 lated about " The star of Bethlehem " appearing in 

 the morning sky. Marvellous descriptions of its 

 apparent form arc also given: but invariablv the 

 " star " has proved really to be the planet Venus, 

 although some members of the general public are 

 very difficult to convince on the point. Under 

 favourable circumstances, and when at its greatest 

 brilliancy, this planet will readily throw a shadow 

 of earthly objects. 



(In be continued.) 



Method of Mounting Fungi in Glycerine. — 

 Mr. A. Lundie, in tin- Transactions and Proceed- 

 ing- of tin' Botanical Society of Edinburgh, recom- 

 mends tin- following method, by means of which 

 the air can in- expelled and bhe filaments teased 

 out when mounting fungi mu-Ii as Eurotium, &c. 

 A piece of E 'n ml i mil is placed on a slide, wi I 

 with chloroform, strong glycerine added, and a 

 cover-glass imposed. By heating the preparation 

 over a Bunsen flame the chloroform is made t>. 

 boil, and .so drive off the last traces of air. Tin- 

 bubbles of chloroform vapour, in passing out. 

 scatter the hyphae and tease out the preparation, 

 without breaking it up. as is done when needles aro- 

 used. 



Meeting of the Royal Microscopical So- 

 ciety.— : At the meeting on May Kith the President, 

 Mr. Carruthers, in the chair, Mr. Charles Baker 

 exhibited two microscopes, one of which, a high- 

 class microscope designed for critical work, was 

 fitted with eyepieces of the new Society standard 

 No. 3, i.e. 1-27 inch. The other instrument, called 

 the '• Plantation " microscope, was very cheap, all 

 complicated parts and movements having been 

 done away with. It is designed for use in the 

 tropics for examining and discovering the ova of 

 internal parasites. Both these instruments we 

 hope to be able to notice at an early date. Dr. 

 Hebb announced that part 8 of Mr. Millett's 

 report of the Foraminifera of the Malay Archi- 

 pelago had been received, and would in due course 

 appear in the Society's journal. Mr. E. M. Nelson 

 read a paper on " The Lag in Microscopic Vision," 

 illustrated by diagrams and a series of tables show- 

 ing proportionate values of the performance of 

 various objectives with eyepieces of various powers. 

 As might be expected, achromatic objectives 

 showed the most marked difference : but even in 

 the case of an apochromatic objective the difference 

 between its performance with a low eyepiece and 

 a high one was shown to vary from 147 to 77. 

 This should finally settle a claim that we have 

 more than once seen advanced on behalf of apo- 

 chromatics, as compared with achromatic*, i.e. that 

 the former will bear the highest eyepiecing with- 

 out any detriment. As regards tube-length, Mr. 

 Nelson's experiments showed that microscopes with 

 short tubes had some advantages with regard to 

 lag over those with long ones. Mr. Nelson also 

 read a paper by Mr. E. B. Stringer on "A New 

 Form of Fine Adjustment," and exhibited a micro- 

 scope made by Messrs. W. Watson & Sons, fitted 

 with the same. There was an excellent exhibition 

 of slides illustrating pond life, due to the courtesy 

 of the Quekett Microscopical Club. 



The Quekett Microscopical Club Journal. 



The April issue of this journal has duly reached 

 us and i.- of much interest. The address oi 



