726 



Popular Science Monthly 



A Gentle but Firm Restrainer for the 

 Insane and Delirious 



A RESTRAINER 

 for the insane or 

 delirious, which has 

 none of the bad ef- 

 fects of the strait- 

 jacket or of tying and 

 holding, is shown in 

 the photograph. It 

 allows the patient the 

 free use of his arms 

 and legs, but at the 

 same time checks any 

 attempt at violence 

 and effectually pre- 

 vents him from get- 

 ting out of bed. 



The fastenings are 

 concealed out of his 

 reach and he can- 

 not work them loose. 



The fastenings are out of the patient's 

 reach and he cannot work them loose. 

 The night-robe conceals the restrainer 



Determining the Best Lighting 

 Conditions for the Eye 



IN spite of its wonderful adaptability, the 

 eye can be impaired by a poor lighting 

 system. Hence it is that the finding of 

 the best lighting conditions is so important 

 a problem. An apparatus which has done 

 much towards the solving of this problem 

 is shown in the accompanying illustrations. 

 It consists in reality of two instruments. 

 One furnishes a variable source of light 

 while the other furnishes a means for view- 

 ing and for measuring this light. 



The first of these instruments is graphic- 

 ally shown in the diagram. A light in the 

 rear of the instrument throws 

 its rays upon an opal glass 

 window after having been sent 

 by a pair of lenses through 

 a "wedge" of blackened glass. 

 By varying the opening in 

 this wedge, the amount of 

 light emitted at the window 

 is made to vary accordingly. 

 The second instrument is a 

 long box-like arrangement. 

 Through this, an observer 

 views the window with one 

 eye. He notes the sensation 

 produced by this light upon 

 his eyes, and at the same 

 time he measures its inten- 

 sity. This measurement is 

 accomplished by means of a 



small "standard" electric light which is 

 placed in the instrument. The light from 

 this lamp is thrown on a mir- 

 ror placed inside the in- 

 strument and adjacent 

 to the front slit. Thus, 

 the light from it and 

 from the window can 

 be viewed at the same 

 time. The light from 

 the small lamp is 

 varied by a shutter 

 which is operated 

 from the outside of 

 the instrument. Be- 

 cause of previous cali- 

 brations, the position 

 in which the shutter 

 is moved will show 

 on a scale the exact 

 intensity of the light 

 let through to the 

 mirror. Hence, by 

 adjusting this shutter 

 until the light from it and from the opal 

 window are the same, the exact intensity 

 of the latter is directly obtained from the 

 calibrations of the shutter scale. In this 

 way the effects of different intensities of 

 light upon the eyes of different individuals 

 are determined. 



Of equal importance to the study of good 

 illumination is the comparison of effects of 

 rapidly varying intensities upon the eyes. 

 Obviously, this apparatus assists here, also. 

 The black wedge varies the intensity and 

 the variation is ascertained by reading the 

 J- difference in the posi- 



j 1 tions of the shutter. 



~N 



lAMP ' 



BLACK WEDGE' 



NOML 

 GLASS 



Arrangement of apparatus for 

 subjecting the* eye to varying 

 brightnesses. At left is a 

 diagram showing the direction 

 of the rays from the lamp 



