HARDWICKE'S SCIENCE-G OSSJF. 



119 



■same as for book packets. It should be remembered 

 that sample packets must not be sealed in such a way 

 ■as to prevent examination if necessary, and that no 

 writing of any description may be enclosed, although 

 printed papers are allowed. The postage, to any 

 part of the world, is now at the rate of one halfpenny 

 per two ounces, except that the lowest charge is one 

 penny. Sample packets are accepted for registration, 

 ■and by this means safe delivery may be ensured. — 

 F. G. Bing, Croydon. 



A Natural Phenomenon, Fireballs at the 

 Cape. — E. S., Cape Town, writes : — " I am glad 

 to be able to say that I saw the phenomenon men- 

 tioned by your correspondent H. in Monday's 

 issue of your paper. The first sight I had of the 

 aerolite would be at an angle of about 50 degrees, 

 and bearing roughly east, and vanished at about 10 

 degrees above horizon in a south-easterly direction. 

 The sight of this falling aerolite was most brilliant — 

 a full sapphire flame of light accompanied by a 

 hissing noise. I saw this phenomenon from the 

 back verandah of a house at Muizenberg, and my 

 time corresponds with H.'' W. G. writes from 

 112, Sir Lowry Road : — " With reference to a letter 

 written by H., which appears in your issue of the 

 1st instant, I may remark that on the day in question 

 I distinctly saw this natural phenomenon. A flash 

 as from a great mirror struck my eyes, and looking 

 towards from whence it came, I saw a ball of fire 

 shoot through the sky and disappear behind the 

 mountains to the east." Mr. S. Riach, Triangle 

 Station, writes : — "As to the paragraph signed H. 

 in your issue or yesterday, I and another here saw 

 the phenomenon on Sunday, 24th ultimo ; in appear- 

 ance it was like a ball of fire slightly elongated. 

 There was no noise when it was first seen, but it 

 seemed to pass through a damp atmosphere when a 

 hissing noise was heard, and a streak of vapour was 

 left in its track. A little further on it appeared to 

 enter a much damper atmosphere, as the sound 

 resembled the noise made when plunging a hot 

 piece of iron into water, and left a large cloud of 

 vapour. The noise then made could have easily been 

 mistaken for a distant peal of thunder. It continued 

 its course afterwards without further trace or noise 

 until it disappeared on the horizon. The time the 

 noise was heard at Worcester was exactly the time 

 the object was seen here, direction was also same." 

 {Caps Argus.)— W. IV. Black, Edinburgh. 



Dr. Leefman has just contributed a valuable paper 

 on the important subject of the purification of water. 

 The system has only been tried on a large scale in 

 the city of Antwerp, where the water-supply could 

 only be obtained from the turgid and impure fluid of 

 the river. The water there is now purified by cast 

 iron and steel borings, placed in cylinders so arranged 

 that by a slow rotation the iron may be continuously 

 showered through the water, whilst the latter is being 

 passed through the same cylinder at a moderate speed. 

 The cylinder is provided with pipes, by which, if 

 necessary, the air may be introduced into direct con- 

 tact with the iron. The iron sometimes, with the 

 carboniferous acid in the water, forms a ferrous car- 

 bonate. On exposure to the air it is converted into 

 ferric hydroxide, which settles down rapidly, and 

 carries down with it and oxidises the organic matter. 

 Dordrecht and Paris are now having parts of their 

 water-supply purified in a similar manner. Iron is 

 Nature's chemical filterer, just as chalk and sandstones 

 are her mechanical filterers. It is equally destructive 

 to microbes and germs generally, and the finest water 



in England is that obtained from the new red sand- 

 stone of Cheshire and elsewhere. 



Is it not a pity the newly-appointed Professor of ■ 

 Astronomy at Cambridge should be attached to 

 sensational astronomy ? His latest prophecy is that 

 the light and heat of the sun will not be available for 

 more than ten millions of years at the most, and 

 possibly not for more than four. This sounds very 

 much like a scientific parody of the Rev. Dr. Cummins 

 and the Rev. Mr. Baxter's Apocalyptic annunciations 

 of the "Speedy coming," etc. The fact is, no con- 

 clusions like those of Sir R. Ball can be accepted as 

 having scientific value unless astronomers first know, 

 and are certain, about the actual temperature of the 

 sun. Numerous attempts have been made to deter- 

 mine the latter, and the results have varied from 

 1,500 to 5,000,000 degrees ! Even Sir Robert Ball 

 allows a range of from four to ten million years for 

 the sun's future duration. That gives a very fair 

 margin. M. Chatelier recently demonstrated before 

 the Paris Academy, that the enormous differences in 

 the estimates of the sun's temperature, result from the 

 fact that different laws have been assumed to repre- 

 sent the rate of radiation. He thinks from his own 

 experiments, that the temperature of the sun's actual 

 body (the photosphere) is higher than 7,600 degrees 

 centigrade, but that the effective solar temperature 

 may be put down at 7>6oo degrees, owing to the 

 cooling effects of the outer solar atmosphere. Geo- 

 logists calculate that life has been existing on the 

 earth in past ages for about one hundred million 

 years. 



The following is a patent recently taken out which 

 all railway companies interested in the comfort of 

 their passengers will at once adopt, especially as a 

 whole carriage can be fitted up with it at a cost of only 

 £4. It is a railway indicator, which puts up the 

 name of every station in successive order as each is 

 passed, in all and each of the compartments at the 

 same time. This simple plan would be a great con- 

 venience to travellers, who would be no longer obliged 

 to strain itheir eyes to catch the name' of a flying 

 station, or to stretch their ears to understand the 

 jargon howled out by indolent porters, or run the risk 

 of being carried past the station they have booked 

 for. It will also abolish those fidgety passengers who 

 seldom travel, and who are continually bothering you, 

 without being satisfied, as to which is the next 

 station. 



Once more, says the "Daily News," we are 

 promised photography in colours, but not, we under- 

 stand, coloured photographs, for it is said that the 

 colours which are taken by the plates need to be 

 projected on to a screen by artificial light. Mr. 

 Frederic E. Ives, of Philadelphia, the inventor of the 

 new process, who has been invited to give two lectures 

 on it before the Royal Society, is on his way from 

 America for this purpose. 



NOTICES TO CORRESPONDENTS. 



To Correspondents and Exchangers. — As we now 

 publish Science-Gossip earlier than formerly, we cannot un- 

 dertake to insert in the following number any communications 

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



To Anonvmous Querists. — We must adhere to our rule of 

 not noticing queries which do not bear the writers' names. 



