f)8 The Aiiiertcdit (reohxjiat. .\u.i,-,i-;t, isgj. 
It is true that at least one astronomer entertains an opinion 
radically different from those above summarized and which 
are shared by most observers. Mr. Holden, of the Lick Ob- 
servatory, in the North American Review for May, 1895, 
writes on the spectroscopic observations ftf Prof. Campbell on 
Mars during the spring and summer of 1894. From a com- 
parison betM'een the absorption bands shown in the spectra of 
that planet and the moon this observer draws the conclusion 
that " there is no more evidence of aqueous vapor or of an at- 
mosphere on the former than there is on the latter. And it is 
in the highest degree unlikely that Mars has an atmosphere 
anything like as dense as the earth's atmosphere at the sum- 
mit of the Himalayas." 
Hence Mr, Holden concludes that "the lakes, oceans, etc., 
have all vanished with the aqueous vapor. It is very unsat- 
isfactory, no doubt, to be unable to answer many questions" 
regarding this planet, but " it is satisfactory to have taken the 
ver}^ important step of clearing the way by sweeping out of 
sight the fabric of assumptions that have barred the path." 
This iconoclastic opinion is in itself so sweeping and soli- 
tary that in spite of its positive tone and the high position of 
the Lick Observatory we may be excused for declining to ac- 
cept it without reserve so long as observers equally experi- 
enced and equally careful cling to their opposing views. We 
are the more fully justified in so doing by recalling the fact 
that Mr. Holden's opinion is qualified with the proviso that 
"the atmosphere of Mars cannot be anything like as dense as 
the earth's atmosphere at the summit of the Himalayas," while 
Mr. Percival Lowell only claims one "less than half of that 
density, though charged with aqueous vapor." So modified a 
denial of previous observations is by no means tantamount to 
disproof. 
Morover, several emphatic contradictions of Mr. Holden's 
conclusions have lately appeared in print. Prof. Huggins and 
Prof. Vogel have both affirmed in the Astrophysical Journal 
that a comparison of the spectra of Mars and the moon does 
show a difference that indicates absorption really due to the 
atmosphere of Mars. And Mr. Jewell in the same periodical 
for April last says that unless the amount of vapor in the at- 
mosphere of Mars is greater than that in October in Baltimore 
