April 27, 1882] 
NATURE 
605 
rotation, and a large amount of black, because the red and green 
impressions have time to die out, and the blue (the most per- 
sistent) remains alone, showing like a fine fluorescent layer over- 
lying the disc. I have not at present the time, or I would 
attempt to find out the excitation-periods for the different colours 
by this method, and I believe that a finer mode of applying it 
might determine the real number of colour-sensations, and allow 
of a decision being arrived at between the theories of Young and 
Hering. J. B. HANNAY 
Dispersal of Freshwater Bivalves 
In the late Mr. Darwin’s interesting contribution upon this 
subject (NATURE, vol. xxv. p. 529), mention is made of the fact 
that the newts in Mr. Norgate’s aquarium ‘‘ frequently have one 
foot caught by a small freshwater bivalve (Cyclas cornea ?),” It 
is, perhaps, worth calling your readers’ attention to a passaye 
which occurs in Mr. Knapp’s ‘‘ Journal of a Naturalist” (2nd ed., 
p- 316), published in 1829, wherein, speaking of the newt, he 
says: ‘‘I have seen the boys in the spring of the year draw it 
up by their fishing lines, a very extraordinary figure, having a 
small shell-fish (Z¢d/ina cornea) attached to one or all of its feet ; 
the toes of the newt having been accidentally introduced into 
the gaping shell, in its progress on the mud at the bottom of the 
pool, or decidedly put in for the purpose of seizure, when the 
animal inhabitant closed the valves and entrapped the toes... .” 
This record, coupled with Mr. Norgate’s statement in the 
article referred to, that ‘‘ newts migrate at night from pond to 
pond, and can cross over obstacles which would be thought to 
be considerable,” seems to point to the fact that the dispersal of 
bivalves by this means is more general than might at first be 
supposed. FRANK J. RowBoTHAM 
The Horse in Motion 
In NATURE, vol. xxv. p. 591, you notice the publication of a 
work entitled ‘*The Horse in Motion,” by Dr. Stillman, and 
remark ; “‘the following extract from Mr. Stanford’s preface 
shows the exact part taken by each of those concerned in the 
investigations.” Will you permit me to say, if the subsequently 
quoted ‘‘ extract” from Mr. Stanford’s preface is suffered to 
pass uncontradicted, it willdo mea great injustice and irreparable 
injury. At the suggestion of a gentleman, now residing in San 
Francisco, Mr. Stanford asked me if it was possible to photo- 
graph a favourite horse of his at full speed. Iinvented the 
means employed, submitted the result to Mr. Stanford, and 
accomplished the work for his private gratification, without 
remuneration. I subsequently sugzested, invented, and patented 
the more elaborate system of investigation, Mr. Stanford paying 
the actual necessary disbursements, exclusive of the value of my 
time, or my personal expenses. I patented the apparatus and 
copyrighted the resulting photographs for my own exclusive 
benefit. Upon the completion of the work Mr. Stanford pre- 
sented me with the apparatus. Never having asked or received 
any payment for the photographs, other than as mentioned, I 
accepted this as a voluntary gift ; the apparatus under my patents 
being worthless for use to any one but myself. These are the 
facts; and on the bases of these I am preparing to assert my rights. 
449, Strand, W.C., April 26 J. MuyBriDGE 
DAILY WEATHER CHARTS IN THE NORTH 
ATLANTIC 
AV Veo append to this notice one of the most important 
statements hitherto issued from the Meteorological 
Office, from which it will be seen that the Meteorological 
Council have resolved to undertake the preparation of 
Daily Weather Charts of the North Atlantic for the 
thirteen months commencing next August. The scheme 
will, without doubt, call forth a co-operation equally hearty 
on the part of the owners, captains, and officers of sailing 
vessels and steamers which cross the Atlantic. 
The figures of the wreck returns for the four years ending 
with June, 1880, show a striking diminution year by year, re- 
sulting as regards the gross totals in a steady reduction from 
1805 in 1876-77 to 891 in1879-80, or less than half the losses 
and casualties to shipping attributable to causes connected 
with the weather round the British coasts. No small 
part of this gratifying result may fairly be claimed as due 
to a gradual improvement in weather-forecasting and to a 
more intelligent attention now generally given to observa- 
tional and instrumental indications of coming storms by 
those who man our fishing boats and coasting vessels. 
That much, however, yet remains to be done in some 
quarters by disseminating even the merest elementary 
notions of the subject was shown by the lamentable loss 
of life on October 14, 1881, on the morning of which day 
whole fleets of boats left the harbours and stood out to 
sea in the face of a barometer which had during the 
previous twelve hours gone down more than an inch, 
The object aimed at is better and fuller information 
than is yet possessed as to the origin, development, and 
progressive movement of the storms which occur over the 
Atlantic. This information will not only immediately 
benefit seamen, but also promote the science of meteoro- 
logy, and thus tend directly to the improvement of the 
weather forecasts and storm warnings issued to the 
British coasts by rendering easier and more certain the 
interpretation of the first indications of approaching 
changes noted at the western stations in lreland and 
Scotland. The commencement of the observations in 
August next has been happily chosen, it being then that 
observations also begin at the international Arctic sta- 
tions, which have been planted by different nationalities 
in Kamschatka, Siberia, Nova Zembla, northern Scandi- 
navia, Greenland, and Arctic North America. There 
will thus be brought to bear on the examination of the 
Atlantic storms a fulness of information gathered from 
these floating and stationary observatories which will so 
largely extend the field of observation chiefly on what 
we may call the weather-side of Europe, not hitherto 
attainable, which cannot but be productive of solid ad- 
vantages to our seafaring population, and to all whose 
material interests may be benefited by a knowledge 
beforehand of weather changes. 
The Meteorological Council, however, act wisely in 
warning against being over-sanguine as to the importance 
of the results to be obtained by the inquiry they are about 
to undertake. No decidedly great step is likely to be 
taken in the improvement of weather forecasting, as re- 
gards time and precision, until either of two things be 
done, namely, till either a cable be laid to Newfoundland, 
vid Faro, Iceland, and Greenland, or till science has 
| taught us to moor a ship 700 or 800 miles out in the 
Atlantic, as a floating meteorological observatory, con- 
nected by cable with the west of Ireland. 
The observations of the temperature of the surface- 
water of the Atlantic it is proposed to make from the 
equator northwards, is one of the most important features 
of the investigation. By these observations, continued 
widely and uninterruptedly over a space of thirteen 
months, the great practical question of the bearing of 
the temperature of the surface-water of the Atlantic, 
particularly between lat. 30° and 50°, on the character of 
coming seasons, can be investigated, and different theories 
on tbe subject be put to the proof. To take an example 
—it has been inquired (NATURE, vol. xxi. p. 142) whether, 
when the temperature of the Atlantic to the south-west of 
the British Islands, is decidedly above the normal tem- 
perature of the season, it does not follow, owing to the 
larger evaporation and other resulting effects, that Atlantic 
storms take a more southerly course than usual in their 
passage across Europe. If the storms of any particular 
winter pursue an easterly course to southwards, of the 
British Islands, that winter will, like the winter of 1870- 
71, be a severe one; but if, on the other hand, these 
storms pursue a course to the northward, the winter will 
partake more or less of the mildness of the winter we have 
Just passed through. Since the character of the season 
thus depends on the line followed by the atmospheric 
disturbances which occur, it results that if the track of the 
storms be dependent on the amount of evaporation from 
