
Fuly 27, 1871] 
NATURE 
243 

the district where they would be most useful and instructive. 
Private collectors would probably show more public spirit, if 
greater zeal and better judgment were shown by local societies. 
F.G.S. 
Science Teaching in Schools 
In the number of NaTuRE for April 20, there is an article 
containing an account of a “ Plan for Teaching Science in Ordi- 
nary Schools, submitted to the London School Board by Mr, J. 
C. Merris.” 
I will ask you to give me a little space for some details respect- 
ing an educational experiment I made in 1867, 1868, and 1869. 
My object was to test the value of a plan much resembling that 
referred to. By means of circulars, addressed to more than a 
hundred of the London clergy, I obtained permission to have the 
children in seven large schools instructed in science. Four com- 
petent teachers put their services at my disposal. One of these 
gentleman is now chemist in iron works, two are art masters, and 
the fourth, having obtained one of the Whitworth Scholarships, 
is a student at Owen’s College. I mention these facts to show 
the sufficiency of their knowledge. Three of them had had con- 
siderable experience in teaching. Twenty-two classes were 
formed, the total number of pupils exceeding 800. The principal 
subjects taught were chemistry, geology, physical geography, 
practical geometry, and mechanical drawing. The lessons were 
from one to two hours in duration on two days in the week at 
each school. But my plan differed from Mr. Morris’s, inasmuch 
as thirty-five to fifty-five lessons were generally given in a subject 
before proceeding to a new one. He suggests that ‘‘a single 
teacher could get through three or four subjects annually, so that 
in two or three years he would have completed the full course 
in each school.” This plan would give from twenty-two 
to thirty lessons per subject if I rightly understand his 
meaning. We fixed a small fee, but seldom obtained it, as 
we found that any attempt to press for payments would have 
reduced very materially the numbers in the colleges. The pupils 
were frequently examined, and those who appeared likely to 
satisfy the minimum requirements of the science department were 
sent in to the May examinations, 
The followiug are some of the observations I made at the 
time :— : 
1. Few of the children appeared to obtain anything like sound 
and comprehensive knowledge of the facts the teachers put 
before them. 
2. The great majority failed to express clearly on paper any 
ideas which an oral examination showed they had gained. 
3. Most of them appeared to forget a subject within a few 
weeks after the discontinuance of instruction, or the substitutioa 
of another branch of science. The utter forgetfulness shown by 
whole classes was sometimes almost startling. 
4. The papers worked by the girls at the examinations were 
superior to those produced by the boys, showing a more intelligent 
knowledge of the subjects they had been taught. This fact may, 
however, have resulted from accident, as comparatively few girls 
received instruction. T. JONES 
The College, Stony Stratford 

Ocean Currents 
Mr. LAUGHTON does not seem to observe that the subject of 
Ocean Currents involves several distinct issues, which may be 
discussed apart from each other. It is, of course, obvious that 
if the temperature explanation of the vertical circulation fails, 
then no illustration of the horizontal circulation, if founded on 
the temperature theory, can be really effective. But it is admis- 
sible to inquire separately whether the horizontal circulation 
would result from a vertical circulatioa such as the tempera- 
ture theory suggests. Jor an objection has been urged against 
the theory on account of the nature of the horizontal circulation 
(see Herschel’s ‘‘ Physical Geography.”) The express object of 
the experiment I have suggested is to show that this particular 
objection is unsound, or rather to illustrate the theoretical con- 
siderations argued in my essay on the Gulf Stream in the Student 
for July 1868. 
But even in so far as my suggested experiment, like the similar 
one carried out by Dr. Carpenter, illustrates the production of a 
vertical circulation, I deny that Mr, Laughton’s objection is 
valid. It is quite unnecessary to havea thermometric gradient 
resembling that in the terrestrial oceans. Whether Dr. Carpen- 
ter’s view be correct, according to which the Arctic regions are 



the place where the Ocean Currents have their birth, or whether 
the view I have advocated be preferable, that the chief source 
of the oceanic circulation is to be recognised in the effects of 
tropical and subtropical heat, it is clear that we are rather con- 
cerned with the integrated effects of one or other cause (or of 
both causes combined) than with the amount by which tempera- 
ture increases per mile of distance towards the equator. As I 
have already remarked, I conceive that any reasoning by which 
the contrary could be maintained would subvert the accepted and 
surely sufficient explanation of the trade and counter-trade 
winds. (lhe experiment described in illustration of this expla- 
nation in Daniell’s Meteorology is open to much graver objec- 
tions than Mr. Laughton has urged against Dr. Carpenter’s ex- 
periment ) And I note that here Mr. Laughton agrees with 
me, except that on the strength of his thermometric gradient 
he is as ready to give up one theory as the other, whereas I see 
no objection to retaining both. 
The very word ‘‘ gradient” should suggest the true answer to 
Mr. Laughton’s reasoning. A gradient of one in ten (say) will 
produce little velocity in a rolling body traversing such an incline 
for a distance of only a few feet, but if the incline be a few miles 
long the body rolling down it would acquire a velocity exceeding 
that of our swiftest express trains. Or again, suppose Dr. Car- 
penter, desiring to illustrate the subject of springs of water, em- 
ployed a conduit-pipe inclined 45 degrees to the vertical, would 
it be any valid objection to the illustration to urge that in most 
natural springs the water gradients are very much less? He 
could surely answer that the principle of his illustration was in 
no way affected by this circumstance, for if the water-gradients 
in nature are small, they act over a much longer range than could 
be emploved in his experimental illustration. So with Mr. 
Laughton’s temperature-gradients ; they are very small indeed, 
but their action extends over a very great distance ; and as in the 
two former cases the total fall measured vertically is to be looked 
upon as the true cause of the resulting motions, so I conceive 
that the total difference of temperature between Polar and Equa- 
torial waters is to be considered in discussing the temperature 
theory of oceanic circulation. 
I note, by the way, that ‘‘solar light” (by misprint or through 
a Japsus calami) was substituted for ‘‘solar heat” in my former 
letter. I did not think it necessary to correct this earlier, as I 
imagined the error would mislead no one. Like Mr. Laughton 
I “‘do not see what effects solar light can ever be supposed to 
produce,” on the ocean, at least, in producing circulation. 
I venture to remind Mr. Laughton that Dr. Carpenter’s posi- 
tion in this matter is very different from his or mine. /Ve have 
theorised on this subject, whether with more or less soundness 
time will show. But Dr. Carpenter has brought striking and im- 
portant facts to our knowledge ; and #/there has been ‘‘an air of 
triumph both in Dr. Carpenter’s lectures and writings” about 
ocean currents, he has had better cause for triumph than the 
mere success of a lecture-room experiment could have afforded 
him. RICHARD A, PROCTOR 
Brighton, July 21 
Western Chronicle of Science 
I woutp beg to be allowed one or two remarks with reference 
to the very favourable review of the ‘‘ Western Chronicle of 
Science” which appeared in last week’s NATURE. 
Tt is not a ‘common Cornish habit to hang heavy jackets, great- 
coats, &c., on the lever of the safety-valve,” and the farmers do 
not, as a rule, “mix guano with limea few days before applying 
the manure.” The editor has seen both these absurdities per- 
formed, and has used them as beacons to wara young men what 
to avoid. I may also remark that Mr. Williams’s Paper is on 
Scientific AZizzng and not Scientific Nursing. 
Falmouth, July 22 J. H. CoLiins 
Formation of Flints 
NOTHING can be more annoying to a reporter than to find he 
has not satisfied those whose statements it has been his duty to 
condense. I have therefore carefully examined the report to 
which Mr. Johnson takes exception in his letter to you of the 
11th inst., and I regret that I am unable to acknowledge any 
error. 
If Mr. Johnson will be good enough to consult some of those 
who were present at the meeting to which he refers, he will, I 
think, be more inclined to admit the accuracy of the report. 
THE WRITER OF THE REPORT 
