KNOWLEDGE & SCIENTIFIC NEWS. 



[Feb., 1904. 



movement of the rudder was a fi action of a second too 

 late to prevent the machine from touching the ground and 

 thus ending the flight. The wiiole occurrence occupied 

 httle, if any more, than one second of time. 



( )nly those who are acquainted with practical aeronau- 

 tics can appreciate the difficulties of attempting the first 

 trials of a flying machine in a 25-mile gale. As winter 

 was already well set in, we should have postponed our 

 trials to a more fa\ourable season, but for the fact that 

 we were determined, before returning home, to know 

 whether the machine possessed sufficient power to fly, 

 sufficient strength to withstand the shock of landings, and 

 sufficient capacity of control to make flij^ht safe in bois- 

 terous winds, as well as in calm air. When these points 

 had been definitely established, we at once packed our 



A Wright Machine— A side view. 



goods and returned home, knowing that the age of the 

 flying machine had come at last. 



From the beginning we have employed entirely new 

 principles of control ; and as all the e.xperiments have 

 been conducted at our owm e.xpense, without assistance 

 from any individual or institution, we do not feel ready 

 at present to give out any pictures or detailed description 

 of the machine. 



It may be mentioned that the Messrs. Wright have for 

 some years been conducting a series of experiments with 

 " gliding machines," that is to say aeroplanes without 

 any engine or propeller. With them the operator starts 

 from the top of a hill and glides down through the air to 

 the bottom, thus having to balance and control the 

 machine. 



We gi\ e here an illustration of one of the gliders, which 

 is probably very similar to the machine recently tried, but 

 the latter apparently had a motor and propeller added. 



^.^^^^^ 

 Electrical Novelties- 



Giant and Miniature 

 S\ins. 



By J. E. Gore, F.R.A.S. 



Messrs. F. Darton and Co.'s list of electrical novelties, just 

 published, is remarkable for the cheapness of most of the 

 articles which this firm supplies. The novelties include 

 house telephones, hand gears and hand-geared dynamos for 

 demonstration purposes, and their vvell-Unovvn small dynamos 

 for working with small oilengines. This firm also has'a num- 

 l)er of attractive small electric light sets and economical 

 motors for fans and light electric power work. 



It was at one time thought a probable hypothesis that 

 the stars were in general of approximately equal size and 

 brightness, and that their difference in brilliancy de- 

 pended chiefly on their relative distance from the earth. 

 On this apparently plausible hypothesis, we should have 

 — taking the accepted " light ratio" of 2-512 — an average 

 star of the first magnitude equal in brightness to 100 

 stars of tfie sixth magnitude. As light varies 

 inversely as the square of the distance, this 

 would imply that a star of the sixth magnitude 

 — that is one just steadily visible to average 

 eyesight in a clear and moonless sky — would 

 be ten times farther from the earth than a 

 star of the first magnitude. For the same 

 reason, a star of the eleventh magnitude would 

 be at ten times the distance of a star of the 

 sixth magnitude, and therefore 100 times the 

 distance of one of the first magnitude. .'\n 

 eleventh magnitude star is about the faintest 

 just steadily visible with a telescope of 3 inches 

 aperture. For stars of the sixteenth magni- 

 tude, or about the faintest visible in a 25-inch 

 refractor, the distance would be — on the above 

 hypothesis — 1000 times the distance of a first 

 magnitude star. 



Although this hypothesis was plausible 

 enough at first sight, there never was any 

 real evidence to show that the stars are 01 

 equal size and brightness, and modern re- 

 searches ha\e proved that they differ greatly 

 in absolute size, and also in intrinsic brilliancy 

 of surface. Measures of distance have shown 

 conclusively that several small stars are considerably 

 nearer to us than some bright stars, such as .^returns, 

 \'ega, Capella, Rigel, and Canopus. These brilliant 

 orbs must therefore be vastly larger than the faint 

 stars which show a larger parallax. On the other 

 hand, we have reason to believe that many stars are 

 much smaller than our Sun. A consideration of some 

 of these giant and miniature suns, as they may be termed, 

 may prove of interest to the general reader. 



We will first consider some of the "giant" suns. 

 The well-known reddish star Aldebaran (a Tauri) in the 

 Hyades maybe taken as a standard star of the first mag- 

 nitude. A small parallax of o'loy of a second of arc was 

 recently found for it at Yale College Observatory (U.S.A.). 

 This makes its distance from the earth about seven times 

 that of a Centauri (of which the parallax is o"-75). Now, 

 as Aldebaran has the same spectrum (K 5 M, Pickering) 

 as the fainter component of a Centauri (magnitude i'75i, 

 the two stars may be considered as fairly comparable in 

 intrinsic brightness. From the above data I find that 

 Aldebaran is about 92 times brighter than the companion 

 of a Centauri and its mass about S82 times greater. But 

 the components of a Centauri are of equal mass, and each 

 equal in mass to our Sun. Hence Aldebaran has prob- 

 ably a mass 882 times greater than that of the Sun ! 



The red southern star Antares (a Scorpii) is of magnitude 

 I -22, according to the most recent measures at Harvard 

 Observatory, and its parallax, according to Sir David Gill, 

 is about o"-o2i. Comparing with Aldebaran, we have the 

 latter 1159 times brighter. But Antares is at five times 



