192 ANNUAL OF SCIENTIFIC DISCOVERY. 



STEEEOSCOPIC COSMORAMIO LENS. 



This is a modification, of the beautiful instrument invented by Sir 

 David Lrewster. The improvement consists in employing, in place of the 

 two small semi-lenses, one large one, -which is rendered stereoscopic by 

 cutting an ordinary plano-convex lens in half, removing more or less of 

 the opposite outer diameters, and then transposing the pieces so that the 

 original centre of the lens becomes the two sides, and the outer edges come 

 together in the middle. The advantage obtained by this arrangement is 

 an increased facility for viewing as one the double pictures. Only one 

 adjustment is necessary for all sights ; viz., increasing or diminishing the 

 distance between the lens and the double picture. 



SELF-REGULATING METEOROLOGICAL REGISTER. 



At the last meeting of the American Association for the promotion of 

 Science, Prof. Webster, of the Virginia Collegiate Institute, read a paper 

 describing a most ingenious, yet marvellously simple, instrument for regis- 

 tering meteorological observations. It consisted of a common clock, the 

 weight of which, instead of running down within the case, runs over two 

 pulleys and down by the side of a cylinder, placed vertically on its end. 

 In the side of- the weight a pencil was placed. The cylinder is surrounded 

 by a sheet of clean paper, 011 which are ruled thirty-two vertical lines, to 

 represent the different points of the compass, and twenty-four horizontal 

 lines, to indicate the hours of the day. Through the cylinder runs a rod, 

 which connects above with a vane ; and as the vane turns, the rod and the 

 cylinder turn. Let the pencil in the weight be placed so near that the 

 point presses upon the paper on the cylinder. Now, if it is calm, the 

 weight running down makes a perpendicular line on the paper ; but if the 

 wind shifts, the mark 011 the paper veers to right or left. If suddenly, it 

 leaves a horizontal mark ; if by degrees, it goes down diagonally. You 

 have to wind your clock when you go to bed, as usual that is all the 

 trouble or, get an eight-day clock, and, by making eight times twenty- 

 four horizontal lines on the paper for as many hours, you wind it but once 

 a week. 



CURIOUS OPTICAL PHENOMENA. 



At the London Polytechnic Institution, a new experiment of a beautiful 

 kind, the invention of a French philosopher, is now being exhibited. It 

 consists in the illumination of the interior of a jet of water, emitted 

 horizontally, and falling into a curve. The light, which is of great 

 brilliancy, is applied at the back of the jet. It seems to be wholly 

 absorbed, and bent out of its lateral rectilinear direction by the falling 

 stream of water, every part of which is rendered perfectly luminous. 





