94 



SCIENTIFIC NEW^S. 



[Jan. 27, iS 



snail he has. I may venture to remark they arejeither 



species of the genera Planorbis or Limncca, as these seem 



most addicted to changing their positions in the manner 



described. F. P. P. 



A CURIOUS PHENOMENON. 



The curious phenomenon pointed out by "Observer" in 

 Scientific News (p. 22) seems to me to be a case of mirage 

 by reflection, seeing that the images in the sky of the shore 

 objects were standing up in the natural position and not 

 inverted as in the ordinary refraction-mirage. The most re- 

 markable instance of reflection-mirage which we have on 

 record is that which was photographed on the 17th of June, 

 1886, off the coast of Madras. On a calm and clear day a 

 boat floating, not far from the port of Madras, and sailors in 

 the act of rowing were reflected in the upper air. The images 

 were distinctly seen in the sky, and when the tide receded 

 the dark image, laid bare, was reflected in the same way. 

 Optical appearances of this kind generally have the images 

 turned upside down. Vince records that at Ramsgate on 

 certain occasions he saw from the water's edge the cliffs near 

 Calais, which, in clear ordinary states of the atmosphere, are 

 generally not visible even from the highlands about that 

 place. 



The ordinary mirage of the desert, which gives the parched 

 traveller the impression of the existence of a sheet of water, 

 is due to the rarefaction of the air in the immediate neighbour- 

 hood of the hot sand. The wonderful images recorded by 

 Scoresby in Arctic regions can be fully explained by one 

 intermediate stratum (or more) between the cold air over a 

 frozen sea and a warm stratum iifty to a hundred feet aloft. 

 In Scoresby 's drawings the images are sometimes direct and 

 sometimes inverted. Inverted images seen in this way are 

 magnified as regards height ; direct images are usually much 

 diminished. On the 14th of December, 1869, between three 

 and four oclock in the morning, the Parisians who were 

 passing on the quay, saw the Louvre, the Seine, and its ports 

 reflected in the sky ; but all the images were inverted as in a 

 mirror placedhorizontally. The moon was then beautifully clear, 

 part of the heavens was veiled with particular clouds which 

 shone with the brightness of an aurora borealis. In the 

 previous year the celebrated aeronaut, Gaston Tissandier, 

 observed a phenomenon quite analogous to the mirage by 

 reflection, pointed out by " Observer," when on a balloon 

 ascent he was over the North Sea. The sea was reflected in 

 the upper regions of the air ; and he, with his friend, M. J. 

 Duruof, saw the image of a steamer which was sailing below. 

 Bernard, of St. Pierre, tells us of the artist Vernet, who in 

 Italy saw the image of a whole town thrown by reflection on 

 the upper sky. Meteorological reports give numerous 

 instances of similar appearances. The mirage in our day 

 does not occur very frequently ; it is always interesting to 

 observe and to take note of. But this photograph of the 

 beautiful reflected mirage will always be of great value in the 

 discussion of the interesting phenomenon. Reader, 



TRANSMISSION OF SIGHT-lMPRESSIONS.i .-. -.,, 

 Great attention has lately, in consequence of certain in- 

 ventions, been drawn to the transmission of sound and even 

 of speech to a distance. But is there any rational hope of 

 our being able to see objects and events at a distance? 

 Leaving out of question matters of pure science, I may ask 

 would it not be invaluable if the manager of a manufactory or 

 a mine could, on looking into a camera, and connecting certain 

 wires, see what was being done in any part of the concern ? 



Lynx. 



RECENT INVENTIONS. 



The following list has been covipiled especially for the Scientific 

 News, by Messrs. W. P. Thompson and Boult, Patent Agents, of 

 323, High Holborn, London, W. C. ; Newcastle Chambers, Angel 

 Row, Nottingham ; Ducie Buildings, Batik Street, Manchester ; and 

 6, Lord Street, Liverpool. 



A Detachable Cuff.- — Mr. G. Benson, of Belfast, has 

 patented a detachable cuff. According to this invention, 

 the outer fold or cuff proper has an inner fold sewn to it. 

 The edge of the wristband of the shirt is concealed 

 between the inner fold and back part of the outer fold or 

 cuff proper. 



Tennis Net Stretcher. — A stretcher for tennis nets 

 has been patented by Messrs. Malings and Muckle, of 

 Woolwich, Kent. The net cord is attached to a swivel 

 fitted to a screw which passes through the pole, and 

 provided with a handle by which the cord and attached 

 net may be stretched. 



Portmanteau. — Messrs. W. H. and B. Jones, of 

 Wolverhampton, have patented an improvement in 

 portmanteaus. It consists essentially of applying castors 

 to the bottom of the portmanteau or box. The castors are 

 attached to bars of wood, which are secured to the 

 bottom of the portmanteau by screws and by end clips. 



ANSWERS TO CORRESPONDENTS. 



J. DE D. — We have no objection to inserting a letter on the 

 subject you refer to, provided it is not more than: half a 

 column in length. 



F. A. — We shall be glad to know the result of your experi- 

 ments. The subject is an interesting one. 



Window Fastener. — A fastener for windows has been 

 patented by Mr. T. Stow, of West Bowling, Bradford, 

 Yorkshire. The fastener consists of a screw, which 

 passes through a block pivotted to supports on the lower 

 window-sash, and engages a pillar secured on the upper 

 sash. When the screw is released from the pillar it can 

 be turned vertical, or nearly so, to allow the sashes to 

 pass. 



Boot and Knife Cleaning Machine. — A rotary 

 machine for cleaning boots, knives, etc., has been 

 patented by Mr. A. E. Haslam, of Cheetwood, Manchester. 

 The machine consists of a horizontal fly-wheel, which 

 receives its motion from a treadle by means of a con- 

 necting rod. The fly-wheel rotates a shaft by means of 

 a friction pulley, and to this shaft brushes, etc., are 

 attached. 



Tobacco Pipe. — Mr. H. Callabine, of Sheffield, has 

 taken out a patent for improvements in tobacco pipes. 

 The stem is formed into a barrel for a pistOil, inserted 

 from the howl end and fixed by a cap or plug. A groove 

 or passage for the smoke is made above the piston. 

 Liquid is drawn in by the piston for cleaning purposes, 

 and a pin is inserted in the piston-rod for cleaning the 

 bowl passage. 



Fabric for Surgical Dressings. — Mr. Gamgee, of 

 Edgbaston, Birmingham, has patented a fabric for surgical 

 dressings. A layer of bleached absorbent cotton is 

 enclosed between two pieces of gauze or muslin. The 

 fabric is perforated with holes to permit free drainage 

 from the wound ; these holes may extend through the 

 absorbent cotton only, or through the whole fabric. 



Respirator for use in Impure Atmospheres. — An 

 apparatus to permit breathing in impure atmospheres has 

 been patented by Messrs. Runge and Stude, both of 



