704 
quently appeared in American journals. Criticism 
which ignores all that is good, and exaggerates all 
that is imperfect, in the work of any specialist, espe- 
cially in that of so eminent a master as Dr. Giinther, 
is greatly to be deprecated. G. BRowNn GOODE. 
Washington, June 1. 
‘A singular optical phenomenon, 
With reference to the ‘optical illusion’ to which 
your correspondent ‘F. J. S.’ drew attention (Science, 
No. 57, p. 275), and which has been abundantly illus- 
trated and explained in later numbers, may I sug- 
gest to your readers who have not yet witnessed the 
phenomenon, to beg, borrow, or buy a few square 
inches of that finely perforated card which ladies 
were accustomed to use a good deal for working book- 
markers, initials, and the like. 
There are several ways of using it with good effect. 
1°. Before cutting the sheet, use it with a hand-mir- 
ror, standing (a) with the back to the light, and look- 
ing through both the real and the reflected cards; (b) 
facing the light, and looking through the one, at 
the other. 2°. Cut off a strip if the quantity availa- 
ble is restricted: otherwise divide in two more equal 
portions, and holding the smaller in one hand, be- 
tween the eye and the larger, vary the distances 
absolutely and relatively, and also the relative in- 
clinations (in their proper parallel planes); in this 
case, also, varying the position with respect to the 
light. 38°. Use the same close to a strong light, in 
such a way that the first surface (and the fourth) 
shall be in shade, while the second, and more espe- 
cially the third, shall be in strong light. 
The variations possible are, of course, far too nu- 
merous to admit of categorical statements. Still less 
can I attempt to describe what is seen. Nor, indeed, 
would it be a sensible proceeding to describe what is 
at once so easy, and so very much more interesting 
to see. My object is merely to point out the means 
and the manner. 
I will, however, mention two of the more curious 
aspects presented. 1°. When aluminous background 
is seen through the reflected screen, and the latter 
is moved freely about in its own plane (which, of 
course, is supposed parallel to the glass), the phantom 
screen remains stationary. 2°. When one screen is 
held at arm’s length, and the other two or three 
inches nearer to the eye, so as to produce a phantom 
some three or four times the size of the real pattern, 
the circumstances are favorable for concentrating at- 
tention on the contrast of colors presented. What I 
see is a sharply-defined rectangular network, as of 
blue steel wires with secondary and tertiary nets of 
doubtful color and indistinct form. As the inter- 
mediate screen is brought nearer to the eye, up to 
halfway, the intensity of color of the blue netting 
is much increased. I cannot pretend to give an exact 
indication, as I have only made a sort of hasty recon- 
noissance of this field. I notice, however, that the 
phenomenon presented by inclining the axes of the 
patterns to each other produces a wonderfully kalei- 
doscopic appearance. 
To pursue the experiments, I should wish to use 
different patterns of perforation, and differently col- 
ored lights. J. HERSCHEL. 
23 Suffolk Street, Pall Mall East, 
London. 
Guyot’s ‘Creation.’ 
In the notice of Guyot’s ‘Creation’ there is an 
error which makes me say precisely the opposite of my 
meaning. On p. 601, first column, fifth line, for ‘ only’ 
read ‘more than.’ WRITER OF THE NOTICE. 
SCIENCE. 
ee ae aes “A, a a4 
[Vou. 1EI., No. 71. 
PRESIDENT ELIOT ON A LIBERAL 
EDUCATION. 
PreEsiDENT Exror’s address before the Johns 
Hopkins university in February last, which ap- 
pears in the June Century, though radical from 
one point of view, is not so from another. In 
maintaining that Greek should no longer be an 
indispensable requisite to the bachelor’s degree, 
he takes what the conservative educators must 
regard as very radical ground. But when we 
examine what he would substitute for Greek, 
and what studies he regards as affording the 
most profitable culture, we see that he does not 
take the same view as the advocates of scien- 
tific education. The studies which he would 
elevate as at least co-equal with Greek, are the 
English language and literature, the French 
and German languages, history, political econ- 
omy, and natural science. <A careful exami- 
nation will show that this proposed change 
would not be the substitution of a scientific for 
a literary culture, but rather the contrary. The 
leading studies in literature are now Greek and 
Latin; the modern languages, literature and 
history, being confessedly taught in a compara- 
tively imperfect way. By adding history and 
the three modern languages to the curriculum 
from which the student makes his choice, a very 
large addition is made to the literary side of the 
banquet. This addition is hardly compensated 
by the increased consideration which he would 
give to political economy and natural science. 
While it seems, therefore, that we can hardly 
regard President Eliot as a pronounced parti- 
san of a scientific education, it must be admit- 
ted that the ground taken by those who are 
such partisans is not very definite. Their 
stereotyped complaint is that too much atten- 
tion is given to languages and mathematics. 
Scientific studies are thus placed in contradis- 
tinction to those two subjects. Now, comparing 
our own education with that of other countries, 
it can hardly be claimed that we pay dispropor- 
tionate attention to either mathematics or lan- 
guages in this country. Notonly is our mathe- 
matical education far behind that of France 
and Germany, but a much better mathemati- 
cal training than our average student gets is 
absolutely necessary to an adequate compre- 
hension of modern physical science. To take 
an example: it is safe to say that the number 
of our college graduates who know mathematics 
enough to understand clearly what physicists 
mean by the terms ‘ conservation’ and ‘ trans- 
formation of energy,’ is very small. One fact 
well worthy of consideration on both sides — 
is, that, notwithstanding that the Germans 
