3^9 



KDooiledge & SeieDtjfle flems 



A MONTHLY JOURNAL OF SCIENCE. 



Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A. 



Vol. III. No. i6. 



[new series.] 



MARCH, 1906. 



SIXPENCE NET. 



CONTENTS see page VII. 



PKotogrsLphs of the 

 CdLiials on Mocrs. 



Readers of " Kxowledge " are mostly aware of the 

 discussions which have from time to time arisen as to 

 the reality of the markings on the planet Mars of the 

 nature of fine lines, and which some suppose to be 

 canals. It has been suggested that these, instead of 

 being distinct lines, are but the edges between grada- 

 tions of half-tones (vide " Knowledge," November, 

 1903). Another theory is that they are the effect of a 

 number of minor detached markings and not continu- 

 ous lines. If, then, a photograph could be taken 

 sulliciently distinct to make out these markings the 

 question could be settled definitely. 



In May last the important announcement was made 

 by Mr. Lowell that the " canals " had been actually 

 photogr;iphed by Mr. Lampland at the Lowell Observa- 

 tory, Flagstaff, Arizona. Persistent endeavours had 

 for some time been made to secure such photographs, 

 but great difficulties were encountered. Eventually a 

 number of exposures were made on a continuous film 

 with short exposures, similar to that of a cinemato- 

 graph. On examination a number were found to show 

 the canals, thus demonstrating indubitably the actual 

 existence of the canals, or, rather, the fine lines on the 

 surf;\ce. 



Mr. Lowell has now been good enough, at our re- 

 quest, to send us some specimens of the actual photo^ 

 graphs. TIk- reproduction whii-h we gi\e herewith 

 may seem somewhat disappointing, but, as mav be 



Miii-li Kediiced p 



imagined, the extreme delicacv of the lines, which, 

 though discernible under a careful examination of the 

 original negatives, can hardly be reproduced in an 

 ordinary photographic print, much less in a half-tone 

 block. This little picture will, however, give some idea 

 of the size and nature of the plate, and beside it are 

 reproduced the careful drawings which Mr. Lowell has 

 made from the original photograph. 



This view shows the Sinus Titanum region, and the 

 following canals are visible in Mr. Lampland's photo- 

 graph : — 



lu'ebus Gigas 



Helicon Laestrvgon 



Cerberus Pallene 



-Styx Boreas 



Kunostos Arion 



Ore us 



At the bottom of the right of the central point in the 

 photograph a projecting nipple may be noticed. This 

 was the first beginning of the new Polar Cap, and was 

 then onlv thirtv-six hours old. 



The telescope used was a 24-inch refractor. 



The p'anet, at the time these photographs were taken, 

 only presented a diameter of about 15 seconds of arc, and 

 in order to secure the necessary definition only the central 

 portion of the 24-inch object glass of the telescope was 

 used, a diaphragm being interposed so as to give an 

 eflfective diameter of 12 inches. A colour screen allow- 

 ing only tlie orange and yellow rays to pass was also 

 employed. 



The Lowell Observatory at FlagstaflT is situated at an 

 elevation of 7250 feet above sea level, and in a particu- 

 larly clear and dry atmosphere, so that the conditions are 

 such as can hardly be obtained at any other observatory. 



luced- Reduced. 



May 20, 

 loh. 42^-45111. 



IMiotoKraph liy 

 C. O. Lampland 



May 22, loh. 20-30111. 



Drawings by Perciv.\l Lowell. 

 X = Martian meridian central at the time. 



May 20, loh. 25-40™. 



