HARDWICKE'S SCIENCE-GOSSIP. 



119 



Hence the spark in sliet^t lightning travels exceed- 

 ingly rapidly to the earth, while in forked lightning 

 it travels slower. In answer to " A Reader " on tha 

 same subject, I may say that the tremendous peal 

 mentioned was due to the bursting of the balls. 

 From the fact of these "fireballs" exploding so 

 violently and retaining their electricity, they have 

 been compared to Leyden jars, but how the principle 

 is carried out in them I cannot say. — Edward B. 

 Parfitt. 



Sheet Lightning. — In confirmation of the ex- 

 planation given by C. Stodder in your number for 

 March, I would ask your correspondents also to ob- 

 ■serve how frequently when sheet lightning is seen in 

 one direction, a thunderstorm, with forked lightning, 

 shortly afterwards comes up from the same quarter 

 of the sky. Is not the sheet lightning, the exhibition 

 of which precedes the storm, the illumination of 

 clouds above the horizon caused by the spark playing 

 in the storm which is coming up, but has not yet 

 reached that part of the atmosphere above our 

 horizon? — C. A. Houghton. 



Sheet Lightning. — In the March number of 

 Science-Gossip, p. 69, I notice a communication, 

 signed Charles Stodder, on " Sheet Lightning," which 

 has brought to my recollection an account by Arago, 

 the French astronomer, of the most continuous sheet 

 lightning he had ever seen ; that confirms your corre- 

 spondent's opinion. It stated that he was at Palermo 

 a day or two afterwards, and ascertained from some 

 Neapolitan seamen, who had come in there, that a 

 violent storm of two or three hours' duration was 

 raging at the time, about 60 or 70 miles off, in 

 the direction at which he noticed the lightning from 

 where he then stood. It was a translated letter that 

 went the round of the English newspapers. — 

 R. T. Rca. 



Composite Candle-wicks Smouldering. — The 

 following explanation of the effect upon the wick of 

 a candle by the light being blown out from above or 

 from below, appears to be sufficient to account for 

 the difference. If the flame be blown out from below 

 a current of tallow flows along the wick and ex- 

 tinguishes the light ; if it be blown out from above 

 the current is retarded in its course, and the wick 

 smoulders down to the tallow. Whilst on this sub- 

 ject it may be well to remark that there is no neces- 

 sity to blow the light out from below in the case of 

 composite candles, as by blowing in the direction of 

 the bent portion of the wick, the wick will be ex- 

 tinguished and smouldering prevented. 



Birds and Fruits. — The benevolent notion that 

 wild fruits are always provided in increased quantities 

 as a provision for the small birds in a hard coming 

 winter, has this past season been dispelled in a rather 

 rude fashion, as may be gathered from the following 

 notes : In iSSo, nuts of all kinds were scarcer by far 

 than we ever remember to have noticed. Whitethorn 

 was unusually shy of flowering, and consequently 

 of fruiting, haws thus being consj^icuous by their 

 absence. Sloes fruited very slightly indeed, which is 

 curious, as it was by no means a bad year for plums. 

 Indeed, but for these the poor wasps would have had 

 but a sad time of it, as apples, pears, and wall fruits 

 were far from plentiful. The only hedge-plant that 

 bore even a moderate crop of berries was the privet, 

 which could hardly have been designed to eke out 

 the food of the small birds, as but very few of these 

 care for privet berries. — James Bitckmaii, Bradford 

 Abbas. 



NOTICES TO CORRESPONDENTS. 



To Correspondents and Exchangers. — As we now 

 publish SciENCE-OossiP earlier than heretofore, we cannot 

 possibly insert in the following number any communications 

 which reach us later than the 8th of the previous month. 



To Anonymous Querists. — We receive so many queries 

 which do not bear the writers' names that we are forced to 

 adhere to our rule of not noticing them. 



To Dealers and others. — We are always glad to treat 

 dealers in natural history objects on the same fair and general 

 ground as amateurs, in so far as the " exchanges " offered are fair 

 exchanges. But it is evident that, when their offers are simply 

 disguised advertisements, for the purpose of evading the cost of 

 advertising, an advantage is taken oi Qwr gratuitous insertion of 

 "exchanges" which cannot be tolerated. 



H. P. — You will find all information respecting the size of 

 South American shrubs, trees, leaves, &c., in the "Treasury of 

 Botany," published by Longmans. 



Dr. H. J. RvbER. — The following books are recommended 

 for Swiss botany : Bouvier's " Flore de la Suisse," published by 

 A. Picard, 82 Rue Bonaparte, Paris, price about ten francs; 

 Weber's " Alpenpflanzen," in 4. small vols., wiih 400 coloured 

 plates, price about 36^. ; " Excursionsflora fiir die Schweiz. 

 Nach der analytischen Methode bearbeitet, von A. Gremli. 

 Dritte verbesserte Auflage ;" Aarau (Christen), 1S78, Svo., size 

 7 X 4i X 578. Dr. Louis Bouvier's " Flore de la Suisse et de 

 la Savoie " is also an excellent work, and of a very convenient 

 size, price 10 francs, published by Picard, Paris. 



W. H. S. — SciENCE-GossiP is now published on the 25th of 

 each month. 



W. D. — You may obtain sets of exotic Lepidoptera from 

 Waikins & Doncaster, 36 Strand. Drury's and Westwood's 

 books are usually advertised in the Natural History Catalogues 

 of W. Wesley, bookseller, Essex Street, Strand. Write for 

 catalogue. 



W. G. W.— Article to hand. " Natural History Notes," 

 edited by F. J. Rowbotham, is a very useful, practical, and un- 

 pretending little serial. 



Aquarium. — You will find details as to various cements for 

 Aquaria, &c., in Taj'lor's "The Aquarium: Its Principles, 

 Structure, and Management," published by D. Bogue, ds. 



G. H. Murray. — "?ou may no doubt get Mr. Mellard Reade's 

 paper on " The Glacial Beds of the Clyde and Forth " from the 

 secretary of the Liverpool Geological Societ}'. 



J. Guardian. — You cannot do better than obtain "A Course 

 of Instruction in Zootomy," by J. Jeffery Parkes, published by 

 Macmillan & Co. It is a first-rate work on the subject, and 

 will afford you all the information you require. 



C. J. Scott. — The green objects found among waterweeds 

 are Planarians. 



A. W. — You may obtain a copy of the rules of the Science- 

 Gossip Botanical Exchange Club by applying to 3 St. Martin's 

 Place, Trafalgar Square. 



R. Beatley. — "The best English locality for green fluor 

 spar is Alston Moor, Cumberland, where it occurs in the Car- 

 boniferous limestone. You may obtain good specimens at the 

 shops of any of the mineralogists who advertise in Science- 

 Gossip. 



R. Baker. — We will try your fluid for mounting. Thanks 

 for the bottle. Write to the manager at the office, 3 St. Martin's 

 Place, for scale of advertisements. 



F. Greening. — The strength of the solutions of liquor sodse 

 and liquor potassse, may be seen by referring to the " Pharma- 

 copceia." Some prefer i drachm of the stick potash, sold in 

 shops, to one fluid ounce of water. 



W. A. H. — Bowerbank's "Monograph of British Sponges," 

 in 3 vols., published by the Ray Society. Dr. Johnston's 

 " History of British Sponges," published in 1842. 



G. T. Baker will find Berge's " Schmettcrlingsbuch " an ex- 

 cellent German book on European Lepidoptera. It contains 

 50 coloured plates, each containing figures of about a dozen 

 insects, published by Julius Hoffmann, Stuttgart, price about 

 20 marks (^i). 



H. A. Francis. — We should be pleased to receive a specimen. 



C. J. Hurt. — You cannot do better than procure Messer's 

 " New and Easy IMethod of studying British Wild Flowers by 

 Natural Analysis," which contains sketches enabling a student 

 at once to assign every British plant to its natural order, pub- 

 li>hed by D. Bogue, 3 St. Martin's Place, Trafalgar Square, 

 London, W.C. Hayward's " Botanist's Pocket-book " is an 

 excellent book for a field botanist. Toad spawn occurs in neck- 

 bead-like strings, and frog spawn in masses. 



EXCHANGES. 



All numbers of " European Ferns " and " European Butter- 

 flies and INIoths " to date, in good condition. What offers ?— 

 J. Badcock, jun., 270 Victoria Park Road, E. 



Perfect, though dead, specimens of Achaiina acicula for 



