112 



HARD WICKE ' S S CIE NCE- G O SSI P. 



Ostrich Farming. — This is one of the most 

 successful of purely modern industries. It had no 

 existence in 1864. At that time the hunting of wild 

 ostriches had effected such havoc that it was feared, 

 with good reason, that ere long the ostrich would be 

 numbered among extinct birds, such as the dodo and 

 the moa. In 1865, about eighty were domesticated in 

 South Africa. In that year the total export of feathers 

 amounted to 17,522 lbs. in weight, valued at ^65,730. 

 It is now estimated that there are 1 50,000 domesticated 

 ostriches living at Cape Colony, giving employment 

 to no less than eight millions of capital. In 1882, the 

 weight of feathers exported amounted 10253,954 lbs. 

 valued at .£1,039,989. Since that the value has 

 considerably diminished, owing doubtless to the 

 abundance of supply. Detailed figures of annual 

 results are given by Mr. P. L. Simmons, in the 

 current volume of the '* Journal of the Society of 

 Arts," page 83. He further tells us that Mr. John 

 J. Matson, of Springfield, Papanni, New Zealand, has 

 succeded in acclimatising and rearing the birds there, 

 and has made his first shipment of 2000 feathers of 

 rare beauty. This in spite of many wise warnings 

 respecting the unsuitability of the climate of New 

 Zealand. 



Electric Welding.— I take it for granted, that 

 everybody who has had any experience in the 

 working of powerful batteries must have had the 

 same experience as myself, viz., that of finding the 

 terminal wires adhering firmly together when brought 

 in contact, and so held for a few seconds. We are 

 now told that electric welding is the latest of the 

 industrial applications of electricity, that Professor 

 Elihu Thompson, of Lynn, Massachusetts, has shown 

 that bars of iron, steel, copper, and brass can be 

 welded firmly together in a few seconds by passing 

 through their junction a very powerful electric current, 

 and that he has invented a special kind of transformer, 

 or induction coil, to enable him to accomplish this 

 operation. In spite of all this, I doubt whether 

 this application of electricity has " already reached 

 a thoroughly practical stage," as anticipated by 

 " Nature." It is easy enough thus to weld the 

 ends of mere wires of small sectional area ; the 

 spark passing between them simply fuses both ends, 

 but in dealing with broad surfaces the demand for 

 electric power to effect such fusion must increase 

 with area, and it is altogether out of the range of 

 practical work to keep such a supply of electric 

 power in readiness for doing that which a common 

 blacksmith's forge fire or an ordinary "roarer," i.e. 

 a soldering gas jet, does so easily and efficiently. 

 Amateur workmen are apt to regard hard soldering 

 and welding as difficult operations, but not so the 

 practical workman, to whom the welding or brazing 

 together of considerable surfaces is merely a routine 

 job, occupying a few minutes. 



It appears from Professor Thompson's own state- 



ment that to weld a steel bar \\ inches diameter, a 

 current of 6000 amperes in volume, and having an 

 electromotive of one-half a volt, is necessary. Other- 

 wise stated, the use of 35 horse power for one minute 

 is required for this operation, which a blacksmith 

 would perform in five minutes with no other ap- 

 pliances than a forge fire, an anvil, a hammer, and 

 a handful of sand. 



Land Surveyors Superseded.— Such will be 

 their fate if the invention of M. Florian de Villepigne 

 fulfils the published descriptions. He has constructed 

 an instrument bearing the ambiguous name of auto- 

 graphometer. It has nothing to do with measuring 

 anybody's autograph, but if carried on a light vehicle 

 and dragged over any given piece of ground it will 

 automatically produce a plan and section showing 

 the form and dimensions of surface, and the differences 

 of level. 



The Viking Ship-Model. — Every tourist who 

 has visited the coast of Norway, north of Bergen, 

 remembers the picturesque ycchts that carry the 

 salted cod from the Nordland fishing stations to 

 Bergen, from whence they are exported to the inland 

 parts of the southern countries of Europe for con- 

 sumption on fast days. The high prows and massive 

 stern, the great single mast and sail, and the general 

 build suggest at once that they are direct descendants 

 and representatives of the ships of the sturdy vikings. 

 I found myself and fellow-tourists all arriving at this 

 conclusion, but on examination of ourselves we could 

 give no satisfactory reason for doing so. It now 

 appears that we were right, in spite of such lack of 

 logic. Mr. G. H. Boehmer, with the aid of some 

 recently discovered remains, such as the boat at 

 Tune, and the remarkable find of a first-class viking- 

 ship under the King's Hill tumulus at Gogstad on 

 the Sandefjord — these and ancient rock-sculptures 

 in Scandinavia all conspire, according to Mr. 

 Boehmer, to prove that the Nordland yechts are 

 exactly like those used by the old Norsemen as far 

 back as the third century or even earlier. 



Origin of Atmosphere Ozone. — A great many 

 theories have been propounded in explanation of the 

 mode of formation of ozone in the atmosphere, the 

 latest of which is that of C. Wurster, whose observa- 

 tions have led him to conclude that it is formed by 

 the action of sunlight on clouds. He states that 

 when clouds are continually formed from above they 

 become highly charged with this active form of 

 oxygen, whilst those formed from below only contain 

 it in notable quantity in their upper layer. This 

 theory has one advantage over many others, it admits 

 of confirmation or refutation both by observation and 

 experiment. Artificial clouds are easily formed, may 

 be confined in glass vessels, and there exposed to 

 sunlight. Ordinary ozonometer paper contained in 



