42 Browning's Neiv Aneroid Barometer. 



one hundredth, of inch, Mr. Browning has provided us with 

 another hand several feet long which iveighs nothing at all. 

 This hand he makes out of a beam of light ! He did not 

 invent these imponderable pointers, which were previously 

 used in other instruments, but he has applied them to his new 

 aneroids. If any reader who has a steelyard, puts a little bit 

 of looking-glass on the beam near the fulcrum, and lets the 

 sunlight fall upon the mirror, he may throw a line of light 

 on the wall of the room, a yard or two off, and when his scale 

 beam moves ever so little, up or down will go the light beam 

 on the wall, marking the oscillations on a greatly enlarged 

 scale. This is Mr. Browning's plan. A mirror, situated as 

 described, receives rays from a lamp suitably placed, and 

 when the beam moves a very little, the light pointer may 

 traverse a scale of several feet. If self-registry is required, all 

 that is necessary is to let the light make its own autograph on 

 sensitive paper, as in the self-registering instruments at Kew. 



Only one of the new aneroids has been finished and tried 

 at the time we write, and it has performed too many peregri- 

 nations to scientific assemblies, to have permitted the exact 

 value of its performance to be ascertained. A good pocket 

 aneroid will beat an ordinary barometer in quickness of 

 response to atmospheric changes ; we may therefore infer that 

 the new aneroid (which is much more delicately constructed) 

 will at least equal, and probably exceed, the sensitiveness of 

 first-class large barometers on the mercurial plan. That the 

 new aneroid is very sensitive, is certain ; but prolonged and 

 careful trials under the same circumstances with the best 

 mercurials is necessary, before an exact comparative state- 

 ment can be made. 



"We hope to see the new aneroid in public institutions and 

 in private houses. For the former it will be of great value, as 

 if suitably placed and protected from the tremors incident to 

 wooden floors, it can enable a whole room full of people to see 

 ts indications without moving from their places. This advan- 

 tage will be obvious to Lloyds, and other establishments 

 where weather changes are anxiously watched. 



We confidently expect the new aneroid will prove to be 

 the best instrument yet constructed, for making noticeable, 

 and registering, the oscillations of the atmosphere during 

 storms, and enabling us to see the rate at which the form of 

 the air waves traverse a given place. When such wave forms 

 pass over us, we are at one time under their crests, and at 

 another under their troughs, and the rate at which such 

 changes take place it would be very interesting and useful to 

 know. 



