Dec. 1st, 1887.J 



SCIENTIFIC NEV/S. 



22c 



cannot study germs without seeing the importance of little 

 things. Almost all the great processes of nature, in as far 

 as they depend on living beings at all, turn on the activity 

 of beings minute, if not microscopic. 



ILLUMINATION OF WATCH DIALS BY 

 THE ELECTRIC LIGHT. 



THE following description of Mr. Charles Humbert's in- 

 vention is taken from the pages of the Deutsche 

 LJhrmacher Zeitung : — 



In the drawing, Fig. i represents the outward appearance 

 of a watch of this kind. 



Fig. 2 is a sectional sketch of the watch case with the 

 lamp, and constituent parts of the illuminator. 



Fig. 3 shows the generator, which may consist either of 

 a bichromate cell or an accumulator, or any other suitable 

 means of supply. 



Fig. 4 illustrates the disposition of the intermitter, in the 



the ground-glass dial upon which the hours and minutes are 

 painted, over which the hands travel. 



The electric lamp J is enclosed in a cavity (Fig. 2) formed 

 in the middle of the case A and of the bezel C. 



The lamp J is fastened on an insulator I (Fig. 2) furnished 

 with a reflector N, and through two conductors X and Y 

 (Figs. 3, 5, and 6), which form a string K connected with 

 the battery L. 



The intermitter attached to the conducting wire, or watch 

 chain, causes the current to be closed by pressing together 

 the arms of the horseshoe. 



This arrangement seems to us particularly adapted for 

 deck watches. 



WEIGHTS AT DIFFERENT AGES. 



A N interesting and not unimportant investigation has 

 ■^ » lately been made about the amount of change that has 

 occurred in our race during successive generations. An 

 old-established wine-firm of the highest class in London, the 



K K 



Watch with Dial Lighted Electrically. 



shape of a horseshoe, connected with the watch chain or 

 conductor. 



Fig. 5 is the upper, and Fig. 6 the lower, view of the lamp 

 and reflector N carried by the insulator I. 



In each drawing like letters represent like parts. 



As in ordinary watch-cases, the middle part, A, Figs. 

 I and ?., is furnished with a cover B and a bezel C. The 

 pillar plate D is secured on the rim of the middle part A of 

 the case. On the pillow plate D(Fig.2) is a polished metal plate 

 fixed by pins and screws, whichhas neitherfiguresnor minute 

 divisions. The latter are painted on a ground-glass plate F 

 (Fig. 2), which is secured to a ring G a short distance from E. 

 The arbors of the hour, minute, and second go through the 

 plate, the space between E and F and the glass plate F (dial), 

 so that the hands travel as usual between the last named 

 and the watch glass H (Fig. 2). 



The inner area of the ring G is conical and polished, and 

 is inclined to the plate E, to equally divide the rays of light 

 that pass through the aperture on to the plate E without being 

 obstructed by the shadows of the arbors of the hands. 



The whole of the above arrangement may be said to 

 consist of a flat reflector, in connection with a ring-shaped 

 reflector and a source of light for the purpose of illuminating 



Messrs. Barry, have kept, for over a century, huge beam- 

 scales in their premises for the use and amusement of 

 aristocratic customers. Upwards of 20,000 persons have 

 been weighed on this balance since the middle of last cen- 

 tury, and the results are recorded in well-indexed ledgers. 

 The weighings were made in ordinary in-door clothing. Mr. 

 Francis Galton, the well-known authority on heredit}', has 

 taken some trouble in selecting the records of the nobility, 

 because the exact ages of that class can be easily ascertained. 

 He has secured notes of age and weight of 1 10 peers and 29 

 baronets. These were born at various times between 1 740 

 and 1830. This interval he has divided into three equal parts, 

 and compare the averages. In the first period the average 

 man weighed, at 25 years of age, 165 lbs. ; at 30, 175 lbs. ; 

 at 40, 185 lbs.; at 50, 188 lbs.; at 60, 185 lbs. ; at 70, 

 180 lbs. In the second period the average man weighed, 

 at 25 years of age, 168 lbs. ; at 30, 172 lbs. ; at 40, 175 lbs.; 

 at 50, 180 lbs. ; at 60, 178 lbs.; at 70, 177 lbs. In the third 

 period the average man weighed, at 25 years of age, 165 lbs.; 

 at 30, 167 lbs.; at 40, 172 lbs. ; at 50, 175 lbs.; at 60, 

 184 lias. ; and at 70, 190 lbs. 



There can be no doubt that the dissolute life led by the 

 upper classes about the beginning of this century, which is 



