HARDWICKE'S SCIENCE-GOSSIP. 



131 



useful work of incubating large numbers of the ova 

 of this species, and will doubtless distribute them 

 judiciously when they are big enough to leave the 

 nursery. 



A Revival. — I have been amused on reading in a 

 contemporary publication the following under the 

 heading, "A New Barometer." " Put a leech in a 

 flask of clear white glass, containing half a litre, and 

 rather wide than narrow. Cover the opening with a 

 piece of coarse cloth, and then there will be a con- 

 venient barometer requiring no more attention than 

 the changing of the water once a fortnight. If the 

 leech is coiled up at the bottom of the flask there will 

 be fine weather ; but when it comes to the surface of 

 the water there will be rain. If it moves about the 

 flask with violence there will be a strong wind ; but 

 should it make somersaults, or have convulsions, 

 there will be a tempest." I remember reading a 

 similar account of this new barometer in " The Boy's 

 Own Book," or "Endless Amusements," when my 

 intellectual faculties were in the course of develop- 

 ment under the stimulating influences of the school- 

 master's cane. This was some years since. By dint 

 of self-denial I saved a sufficient number of coppers to 

 purchase a leech and suitable bottle. But there was 

 something wrong either with the animal or the 

 weather. In spite of great efforts to reconcile their 

 movements with the description I failed. In the 

 extreme case of tempest this may have arisen from 

 my want of skill in diagnosing the symptoms of leech 

 convulsions. I have no recollection of the perform- 

 ance of any somersaults, but can distinctly repicture 

 a. very characteristic movement by which the animal 

 became alternately hoop-shaped and straight ; but it 

 did this in fine weather and other weather indis- 

 criminately. Further observations in a wider field, 

 supplied by a leech aquarium in the window of a 

 druggist's shop, only multiplied the discrepancies. 

 Some of the leeches went in for fine weather at the 

 same time that others were vigorously predicting 

 storms. 



The Preservation of Telegraph Poles. — 

 This has now become a business of some importance, 

 the amount of capital invested being very great, and 

 the tendency to decay so serious where wood is still 

 used. Norway is remarkably well served with tele- 

 graphic communication. I doubt whether any other 

 country has, in proportion to its population, so large 

 a mileage. The wires there follow not merely the 

 railways, but most of the ordinary roads. A method 

 is now adopted there for' preserving the wood, which 

 is said to be eminently successful. A hole about 

 three-quarters of an inch in diameter is started at 

 about two feet from the ground, and bored with a 

 downward slant towards the centre of the pole. 

 About a quarter of a pound of powdered sulphate of 

 copper is rammed into this hole, which is then closed 



with a wooden plug. The humidity of the wood 

 gradually dissolves the salt, and the solution diffuses 

 itself through the pores of the wood by capillary 

 action. As it thus spreads the wood assumes a 

 greenish hue, and the supply of salt is renewed as it 

 dissolves and passes from the hole. The antiseptic 

 properties of copper salts are well known. Railway 

 sleepers and many other structural elements may be 

 thus treated. 



Another Use of Luminous Paint. — Herr 

 Stehle, the Government Inspector of the Royal 

 Bavarian Theatre, reports that in the National and 

 Royal Court Theatres sheets of cardboard, painted 

 with the word Ausgang (way out), have been placed 

 in the corridors and other parts, and that on turning 

 off the gas they become sufficiently visible to guide 

 the audience in the midst of the darkness. As 

 turning off the gas is demanded in cases of partial 

 fire, it is believed that such placards may mitigate 

 the disasters that have occurred, as in the case of the 

 Jewish Club at the East end of London, where 

 seventeen lives were lost in the course of a few 

 minutes. 



The Equinoctial Gales. — Popular beliefs are 

 very stubborn. " So much the worse for the facts," 

 is the popular verdict when facts are brought against 

 tradition. Among people who never fail in their 

 aspirates, and therefore claim to be highly educated 

 and utterly superior, we continually hear of sea- 

 voyages being postponed in order to escape the 

 equinoctial gales. September is dreaded, and even 

 avoided at much inconvenience, although meteoro- 

 logical records, and the common experience of 

 practical sailors, place it among the least stormy 

 months of the year. The most stormy period of all 

 falls about midway between the autumnal and spring 

 equinoxes, at the farthest possible distance from 

 either, i.e. about the end of December and the early 

 part of January. At the Meteorological Conference 

 of 1884, Mr. R. H. Scott stated these facts in detail, 

 taking an average of fourteen years from 1870. The 

 records of the Meteorological Office show that the 

 most stormy period of the year is that of the winter 

 months. This is perfectly well understood by sailors. 

 Many ships are provided with two sets of sails, winter 

 sails and summer sails ; the winter sails being of 

 thicker and stronger canvas than the summer sails, in 

 order that they may resist the stronger winds. I never 

 heard of equinoctial sails, which should be provided 

 if the equinoctial gales were other than mythical. 



The evidence supplied by our British records are 

 further confirmed by observations made in other 

 countries. Thus, Dr. R. Miiller publishes, in the last 

 April number of " Mittheilungen aus dem Gebiete 

 des Seewesens," an analysis of the records of the 

 Anemometer of Pola, from 1S76-86. Sixty-three per 

 cent, of the strong winds and gales in the Adriatic 



