__ : REVIEW OF REVIEWS 



ous labour of the diver. This mat- small boat plunges this end into the 



- and the reason therefore is enter- water and looks through the other. Or 



discussed bv Ernest course a high degree of transparer 



in a late number of the R Scienti- in the water is presupposed. 



Paris If the exterior light still penetra 



Tr or the seeminglv anoma- too much the tube is covered with 



lo imstance of cle :sion at black cloth, such as photographers use 

 a STeat elevation above the water than 



near it he thus explains lighi reflected ^ the surface and the 



re nlv the light proceeding from ini- 



the water, do matter how m ersed objects After a moment, when the 



- not absor the light e j,as ^j sufficient repose from the ont- 



" - >arface: a pa: _^ e ii 2 h t% an d i n . the water is not 



at light - -efleeted as from a doubled, one perceives clearly this srrange 



mirror. -i^ tatt5 f^. ^ lii-]e explored. 



This especially evident towards A s:miiar device 5 found in the 



hen the brilliant colours of the u g i a5S -bottomed boats in use along the 



. are dazzlingly reflected from the c ^_ t of Ca i ifom i^ ^ elsewhere in 



water, and even when the sun is veiled tropical wate _. These have thick 



the same thing is shown by the fact that plates of gl „ .- nto the bottom, each 



the water looks blue or grey according covered ^^ a j^yy 3 lide which can 



as the sky is clear or clouded. ^ qu £ckly dosed in case of accidental 



-. hreakinor of the ffla-^ \n awnine cuts 



This phenomenon or reflection contributes l»c«uvau «x ... _. 



doublv :o the masking of submarine depths, off the exterior light and the passen- 



N the sub- . fascinated upon the im- 



mersed objects, but the reflection daxEles & - r 



-. --. . - . :--:.::- - ' I ' ° 



But the reflecting power of the water ceep. 

 auamt: its obliquity of the r.v - _. 



WL its surface, and the obser- The writer clc?*r- :~Zl a warm plea 



whose position is elevated to a surr .-__ _•„_ ^. ..^ ...... - - ^ ^ - ;-j.-j-. --- 



hei«hi- r es ger quantitv of vertical 



„ : es wherever water sufficiently clear is 



e brilliance found, believing that aluable 



lection diminish— :entific data mav thus be gathered, 



marine depths augments, because the . , _ . , 



of the observer : a greater qu N or 15 the spectacle to be despised 



- - a direct propor- r_ ^ noint of be ilone 



rice : just as in a landscape f 



ie background is more luminous than the Concerning this he quotes from 



Gonce - Voyage Autour du Monde." 

 M. Constet proceeds to observe that - — 



it is not necessarv, however, to ma 

 use of a balloon or an aeroplar. 

 secure this direct vision of submerged 

 objects. Such vision may be obtained 

 mple expedient of cutting off 

 the reflected This is accomplished 



xb» unpretentious optical instrument 

 known as the "Dib : zex 



- a light tube ab 

 "ittle mere than six feet :: 



ty is 

 5S "ate The observer, sea 



- 



. . 



- ; - 



- 



- — - i ■ . ,- — 



i, from the green of 



- - - - . . - 



" - - -. . - - ■ --.. 



res .... I 



&een obscured for au 



. :.. ir: '.a ..-..- : .-:e 



_ - - - . - . - 



Krh 



r. : -•-'. :~e zi:r.:.:-: -- 



