SCIENCE NOTES.

Digger (Invercargill RSA), Issue 12, 4 June 1920, Page 14

SCIENCE NOTES.

WORLD 'S TALLEST CHIMNEY. The recently -finished smelter chimney at Anaconda, Mont., is now claimed as the tallest and also as the biggest chimney of the entire world. Its height is 585ft 1^-in. The inside diameter at the top is 60ft; so that it delivers to the general atmospherc a mighty stream of stacx gas. Ihe chimney was built because Uie company proposed to instal. an electro system for the treatment of metallurgical smoke with a view to the recovery of valuable metallic material. The purpose of this chimney is to creat-e a draught in and effect a disposal of the smelter gases,-and thus perform its part in the reclamation from the metallurgical smokc of gold, silver, copper,- and arsenic which would otherwise be wasted. Ths fumes carrving these materials are produced hy the convertefs, roasters, and reverberators. it. is expected to recover some 32 tons of arsenic per day of operation. FLYING UPSIDE DOWN.

During the war there were reports more than ouce of airmen, who flying at great heights and getthrg involved in dense clouds lost all their bearings and found — when they recovered the means of observation — that they had been flying "upside down" without knowing it. The average non-scientific reader, it is safe to assume on reading such accounts, took them in a fanciful and not a literal sense ; could not imagine that a man might be for some t'.me head downwards as regards earth and yet feel himself to be sittir.g upright. But, fcJir Frank Dyson pointed out in a recent lecture, that, according to the Einstein Theory of Gravitation, this "flying upside down" without being aware of the fact was quite natural. The flying man could not in his machine detect the difference hetween gravitational force and the force provided by his machine when he was deprived of his earth means of observation. FLESH - EATIN G PLANTS. Oue of the most extraordinary forms of plant life in existence is the common Engli&h sundew. The plant is carnivordus. It catches insects and eats them. A scientist recently inado an interesting experiment wiin this plant. A few inches from tne h.airy leaf of a sundew plant he suspended a, tiny fragment of meat. This he at once phr.tographed. and then waited forty minutes, after which time the leaf of the sundew had bent over, and was appreciabiy nearer to its dinner. After the lapse of another forty minutes the plant was close up to the meat, some of its hairs actuafly touching it, and a little later the leaf entirely enveloped its meal, and was left to digest it. Another plant, called Venus' fly-trap, catches flies in a kina of trap. The edges of the leaves are prcvided with spikes, and may be compared to a human mouth halt"open, the spikes corresponding to the teeth. If an insect- settles upon one of these leaves it closes in a few seconds, and then digests the insect. STAIN ED GTiASS WINDOWS. The restorati , i of stained glass windows which has ! ■ en done hitherto in old cathedrals or c' er structure is for the mc«t part impn rly earried out, says a French expert. It is observed that the wii.dows of the . liddle Ages were composed of an asse: blage of coloured glass which made up a veritable niosaic. But, it is not as well known that the pieces wero cut out of disk-shaped glass plates called cives, whose thickness was quite variable in the same plate, being thinner at the edges than at the centre. There irrcgularities aided greatly in increasing the effects of light, thus adding greatly to tlc heauty of the windovv. Colours were obtained by the use of metallic oxides, hut not in the same way as they are employcd at present, for they were not intrcduced in the pure state, but remained mixed or combined with their natural imj urities. For this r.eason the tones of the glass were very different from what are produced by modern Industry. There is however no ditficulty in producing the glass in cives and coloured by the old prccess, and this is not by any means a lcst art. It is only by the negligence of the architects that the old form of glass is re placed by flat panes, these being coloured in modern crude tones.