C. E. Burton.—Physical Observations of Mars. 171 
this notice, reveals the fact that Huggins Inlet* has by no means ceased to exist, as it 
is plainly visible in both the latter series of drawings, Schiaparelli having designated 
it the Canal of the Cyclops. See also Nos. 15, 16, 18, 19, 20, 21, of the present series. 
The streak running N. W, from Christie Bay is beautifully shown in Dawes’ drawings. 
Great caution is therefore necessary in asserting that any ‘canal’ is a recent 
formation, considering our present almost total ignorance of the forces and other 
conditions which are able to efface for years together markings at other times so 
distinctly visible that a tolerably extensive acquaintance with earlier records alone 
saves the observer from fancying himself a discoverer of new details. 
There is little risk of error in the assertion, that as instruments of high quality 
increase in number, and as observers become more skilled, many of the discrepancies 
between their results will disappear, or will be distinctly veferable to changes in the 
planet itself. 
From this point of view we must regard all the charts of Mars hitherto compiled, 
as in great part provisional, and many years will probably elapse before an 
authoritative map of the entire surface of the planet can be prepared, even supposing 
that no real changes are in progress there. 
If the notes and drawings now laid before the Royal Dublin Society, help in any 
degree toward the attainment of this object, their authors} will be well repaid for 
their trouble. 
APPENDIX ADDED IN PRESS. 
Sketch map of the Region of Mars included between the 350" and 60 degrees of Longitude and the 
parallels of 50° north and 20° south Latitude, with remarks by Dr. J. V. Schiaparelli, Director of the 
Royal Observatory of Brera, near Milan. 
Long. 0° 30° 60° 90° 
Lat. 
+ 10° 
0° 
49° SH AL 
* According to Schiaparelli, Huggins Inlet can scarcely be identical with the Gulf of the Cyclops. But 
see remarks on page 159; also Dr. Terby’s comparative Table of Nomenclatures. Bulletins de ? Academie 
Royale de Belgique, XLVIIL, 12, pp. 6-15, for numerous identifications. 
+ Mr. Dreyer’s responsibilities in connexion with the preceding paper extend only to the drawings 
and original notes on the same, which he has kindly contributed to it at my request. 
2F 
