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A LARGE GROUP OF SUN-SPOTS.-Despite the fact that that the parallax of the double star I 2398 is 0-484". This we are now drawing near to a sun-spot minimum, the solar star thus becomes the nearest known neighbour, in the disc has, during the past fortnight, exhibited an extensive northern sky, to the solar system, its distance being 420,00 group of spots. An observation on August 28 showed a astronomical units, or 6.7 light-years. A previous observa. bright patch of faculæ some distance south of the equator tion by Lamp, at Kiel in 1883-7, gave the parallax as on the eastern limb, and on the following day a small 0.353". spot was observed near the limb to the north of this. Observations on September 6 showed that there was a group of small spots in about the latitude of the previously

OUR FOOD FROM THE WATERS.1 observed faculæ, and this developed until, on September 11, it was a diamond-shaped group, of medium-sized spots, of AT the last meeting of the British Association in Canada

(Toronto, 1897) I was able to lay before Section D which the longest diagonal was about one-sixth the length

a preliminary account of the results of running sea-war of the sun's diameter; each of the four main spots was

through four silk tow-nets of different degrees of fineness surrounded by a number of smaller nuclei.

continuously day and night during the voyage from Lives THE TRANSVAAL OBSERVATORY.-From a note in the pool to Quebec. During the eight days' traverse of the Observatory (No. 413, p. 369) we learn that the Transvaal North Atlantic, the nets were emptied and the contents Government, on behalf of the Government observatory, examined morning and evening, so that each such gatherhas accepted the gift of a photographic astronomical ing was approximately a twelve-hours' catch, and each telescope from Mr. Franklin Adams. The triple-objective day and each night of the voyage was represented by four is of 10 inches aperture, and made by Messrs. Cooke and gatherings. This method of collecting samples of the Sons. Two guiding telescopes, each of 6 inches diameter,

surface sauna of the sea in any required quantity per day accompany the main instrument. The telescope is erected,

or hour froni an ocean liner going at full speed was and is to be employed mainly in assisting Prof. Kapteyn, in

suggested to me by Sir John Murray of the Challenger his studies of the construction of the sidereal universe, by Expedition, and was first practised, I believe, by Murray securing photographs of the southern heavens.

himself in crossing the Atlantic. I have since been able

to make similar traverses of several of the great oceans, ARTIFICIAL IMITATION OF LUNAR LANDSCAPE.-By cooling in addition to the North Atlantic, namely, twice across the slag from an iron-ore, smelted in a furnace and run

the equator and through the South Atlantic, betwera off at a temperature of about 1100° C., Mr. Paul Fuchs

England and South Africa, and four times through the succeeded in obtaining a surface structure which appears Mediterranean, the Red Sea, and the Indian Ocean to to be a very good imitation, in miniature, of a typical Ceylon; and no doubt other naturalists have done much lunar landscape. The cooling was done with water applied the sanie. The method is simple, effective, and inin various ways, and produced craters, mountains, and expensive ; and the gatherings, if taken continuously, give plains according to the conditions of the slag and of the

a series of samples amounting to a section through the cooling. Photographs of the results are reproduced on a surface layer of the sea, a certain volume of water being plate accompanying No. 4348 of the Astronomische Nach- puniped in continuously through the bottom of the ship. richten, wherein Mr. Fuchs describes his experiments. and strained through the fine silk nets, the mesh of which

TEMPERATURE AND PRESSURE CONDITIONS IN THE SOLAR may be one two-hundredth of an inch across, before passe ATMOSPHERE.—Two interesting letters dealing with the

ing out into the sea again. In examining with a microconditions obtaining in the solar atmospheres appear in

scope such a series of gatherings across an Ocean, two No. 413 of the Observatory (September, pp. 359-63).

facts are brought prominently before the mind :-(1) the In the first, Mr. Buss returns to the question of the

constant presence of a certain amount of minute living radial motions in sun-spots exhibited by Mr. Evershed's

things; (2) the very great variation in the quantity and in spectrograms, and shows how they may be interpreted to

the nature of these organismis. indicate that the visible umbral area of a spot is caused

Such gatherings taken continuously from an ocean lin-t by the efflux of material from within rather than the influx

give, however, information only in regard to the surface of cooler matter, from above. The facts that spots often

fauna and flora of the sea, including many organisms of endure for months, and that Mr. Evershed finds that the

fundamental importance to man as the immediate or the radial motions are confined to the “reversing layer,i.e.

ultimate food of fishes and whales and other useful to the lower levels of the sun's general atmosphere, are

animals. quoted as supporting this view; the vortices are effects of

It was therefore a great advance in planktology when the outrush. This idea of the spots being produced by

Prof. Victor Hensen (1887) introduced his vertical, quantieffluence leads to the sequel that the vapours of the actual

tative nets, which could be lowered down and drawn up spot must be at a higher temperature, whereas the observa

through any required zones of the water. The highly tions of Sir Norman Lockyer and others show the reverse.

original ideas and the ingenious methods of Hensen and To overcome this difficulty Mr. Buss suggests that the

his colleagues of the Kiel School of Planktology—whether spectrum observed is that of the vapours high above the

all the conclusions which have been drawn from their visual uinbral level, and that, could we but observe the

results be accepted or not-have at the least inaugurated unveiled spectrum of the umbra itself, we would find it

a new epoch in such oceanographic work, and have in. to be a bright-line spectrum.

spired a large number of disciples, critics, and workers In the second letter Mr. Evershed continues the dis

in most civilised countries, with the result that the discussion with Prof. Whittaker regarding pressure in the

tribution of minute organisms in the oceans and the fresh “ reversing layer.” After' quoting experimental evidence

waters of the globe is now much more fully known than to show that pressure-shifts are apparently independent of

was the case twenty, or even ten, years ago. But perhaps the manner in which luminosity is produced, Mr. Evershed

the dominant feeling on the part of those engaged in this points to the fact that the spectrum of the “ reversing

work is that, notwithstanding all this activity in research layer consists of bright lines, as demonstrating that there

and the mass of published literature which it has given is no enormous pressure on the emitting vapours; other

rise to, much still remains to be done, and that the wise one would expect

continuous spectrum.

planktologist is still face to face with some of the most Finally, he states that measures of spot spectra, made at

important unsolved problems of biology. Kodaikanal, do exhibit small, differential pressure-shifts ;

It is only possible in an address such as this to select the most affected lines are slightly displaced, relatively,

few points for demonstration and for criticism-the towards the violet, thus indicating a pressure in the

latter not with any intention of disparaging the stimuumbræ of about one-third of an atmosphere less than in

lating work that has been done, but rather with the view the surrounding regions. Further details of these results

of emphasising the difficulties, of deprecating premature are to be published shortly.

conclusions, and of advocating more minute and more

constant observations. PARALLAX OF THE DOUBLE STAR I 2398.-In No. 4348 of

The fundamental ideas of Hensen

that the the Astronomische Nachrichten (p. 63), Dr. Karl Bohlin plankton, or assemblage of more or less minute drifting announces that the reduction of photographic observations, made at the Stockholm Observatory during 1907-8, shows

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1 Evening discourse delivered before the British Association at Winnipeg

on August 31 by Prof. W. A. Herdman, F.R.S.

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organisms (both animals and plants) in the sea, is uniformly called “ sea-sawdust." Many othe: naturalists since have distributed over area where the physical conditions seen the same phenomenon, caused both by this and by are approximately the same, and that by taking a com- other organisms. It must be of common occurrence, and paratively small number of samples it would be possible is widespread in the oceans, and it will be admitted that a to calculate the quantity of plankton contained at the time quantitative net hauled vertically through such a trichoof observation in a given sea area, and to trace the changes desmium bank would give entirely different results from of this plankton both in space and time. This was a a haul taken,

be, only a mile or two away, in sufficiently grand conception, and it has been of great water under, so far as can be determined, the same physical sei vice to science by stimulating many workers to further conditions, but free from Trichodesmium. research. In order to obtain answers to the problems Nine nations bordering the north-west seas of Europe, before him, Hensen devised nets of the finest silk of about some seven or eight years ago, engaged in a joint scheme 6000 meshes in the square centimetre, to be hauled up of biological and hydrographical investigation, mainly in from the bottom to the surface, and having their constants the Norih Sea, with the declared object of throwing light determined so that it is known what volume of water upon fundamental facts bearing on the economic problems passes through the

net

under certain conditions, and of the fisheries. One important part of their programme yields a certain quantity of plankton.

was to test the quantity, distribution, and variation of the Now if this constancy of distribution postulated by plankton by means of periodic observations undertaken four Hensen could be relied upon over considerable areas of the times in the year (February, May, August, and November) sea, far-reaching conclusions, having important bearings at certain fixed points in the sea. Many biologists conupon fisheries questions, might be arrived at; and such sidered that these periods were too few' and the chosen have, in fact, been put forward by the Kiel planktologists stations too far apart to give trustworthy results. It is and their followers-such as the calculation by Hensen possible that even the original promoters of the scheme and lpstein that the North Sea in the spring of 1895 con- would now share that view, and the opinion has recently tained at least 157 billions of the eggs and larvæ of certain been published by the American planktologist, C. A. edible fisi ; and from this figure and the average numbers Koloid-than whom no one is better entitled, from his of eggs produced by the fish, their further computation own detailed and exact work, to express an authoritative of the total number of the mature fish population which verdict-that certain recent observations can but reveal produced the eggs-a grand conclusion, but one based upon the futility of the plankton programme of the International only 158 samples, taken in the proportion of one square Commission for the investigation of the sea. The quarterly metre sampled for each 3,465,968 square metres of sea. examinations of this programme will, doubtless, yield some Or, again, Hensen's estimation, from 120 samples, of the facts of value, but they are truly inadequate to give any number of certain kinds of fish eggs in a part of the West trustworthy view of the amount and course of plankton Baltic, from which, by comparing with the number' of production in the sea.

That is the latest pronouncesuch eggs that would normally be produced by the fish ment on the subject, made by a neighbour of yours to the captured in that area, he arrived at the conclusion that south, who has probably devoted more time and care to the fisherman catches about one-fourth of the total fish detailed plankton studies than anyone

else this population--possibly a correct approximation, though differ- | continent. ing considerably from estimates that have been inade for It is evident that before we base far-reaching the North Sea.

generalisations upon our plankton samples, a minute study Such generalisations are most attractive, and if it can of the distribution of life in both marine and fresh waters be established that they are based upon sufficiently trust- at very frequent intervals throughout the year should be worthy data, their practical utility to man in connection undertaken. Kofoid has made such a minute study of the with sea-fishery legislation may be very great. But the lakes and streams of Illinois, and similar intensive work comparatively small number of the samples, and the is now being carried out at several localities in Europe. observed irregularity in the distribution of the plankton Too little attention has been paid in the past to the (containing, for example, the fish eggs) over wide areas, distribution of many animals in swarns, some parts of such as the North Sea, leave the impression that further the sea being crowded and neighbouring parts being destiobservations are required before such conclusions can be tute of such forms, and this not merely round coasts and accepted as established.

in the narrow seas, but also in the open ocean. For Of the criticisms that have appeared in Germany, in the example, some species of Copepoda and other small United States and elsewhere, the two most fundamental crustacea occur notably in dense crowds, and are not are :-(1) that the samples are inadequate; and (2) that universally distributed. This is true also of some of the there is no such constancy and regularity in distribution diatoms, and also of larger organisms. Many naturalists as Hensen and some others have supposed. It has been have remarked upon the banks of Trichodesmium, of shown by Kofoid, by Lohmann, and by others that there Medusa and Siphonophora, of Salpæ, of Pteropods. of are imperfections in the methods which were not at first Peridinians, and of other common constituents of the realised, and that in some circumstances anything from plankton. Cleve's classification into Tricho-Plankton 50 to 98 per cent. of the more minute organisms of the (Arctic), Styli-Plankton (temperate), and Desmo-Plankton plankton may escape capture by the finest silk quantitative (tropical) depends upon the existence of such vast swarms

The mesh of the silk is 1/200th inch across, but of particular organisms in masses of water coming into the many of the organisms are only 1/3000th inch in diameter, North Atlantic from different sources. and so can readily escape.

It is possible that in some parts of the ocean, far from Other methods have been devised to supplement the land, the plankton may be distributed with the uniformity Hensen nets, such as the filtering of water pumped up supposed by Hensen. It is important to recognise that at through hose-pipes let down to known depths, and also least three classes of locality exist in the sea in relation the microscopic examination in the laboratory of the centri- to distribution of plankton :fuged contents of comparatively small samples of water (1) There are estuaries and coastal waters where there obtained by means of closing water-bottles from various are usually strong tidal and other local currents, with zones in the ocean. But even if deficiencies in the nets rapid changes of conditions, and where the plankton is be thus made good by supplementary methods, and be largely in Quenced by its proximity to land. allowed for in the calculations, there still remains the (2) There are considerable sea areas, such as the centre second and more fundamental source of error, namely, un- of the North Sea and the centre of the Irish Sea, where equal distribution of the organisms in the water ; and in the plankton is removed from coastal conditions, but is regard to this a large amount of evidence has now been influenced by various factors which cause great irregularity accumulated, since the time when Darwin, during the in its distribution. These are the localities of the greatest voyage of the Beagle on March 18, 1832, noticed off the economic importance to man, and to which attention should coast of South America vast tracts of water discoloured by especially be directed. the minute floating alga Trichodesmium erythraeum. (3) There are large oceanic areas in which there may which is said to have given its name to the Red Sea, and which Captain Cook's sailors in the previous century

1“ Internationale Revue der H ydrobiologie und Hyrrogias hie," vol. i.

p. 846. December, 1908. I It is probable that too high a figure was taken for this.

2 See Dakin, Trans. Biol. Soc. Liverpool, xxii , p. 544.

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be uniformity of conditions, but it ought to be recognised rapidity, the plankton becomes more uniformly distributed, that such regions are not those in which the plankton is and a comparatively small number of samples may then of most importance to men. The great fisheries of the be fairly representative of the whole. That is probably world, such as those of the North Sea, the cod fishery in more or less the case with fresh-water lakes, and I have Norway, and those on the Newfoundland Banks, are not noticed it in Port Erin Bay in the case of Diatoms. Ir in mid-ocean, but are in areas round the continents, where spring, and again in autumn, when suitable weather the plankton is irregular in its distribution.

occurs, as it did two years ago at the end of September, As an example of a locality of the second type, showing the Diatoms may increase enormously, and in such circumseasonal, horizontal, and vertical differences in the distribu- stances they seem to be very evenly spread over all parts tion of the plankton, we may take the centre of the Irish and to pervade the water to some depth ; but that is Sea, off the south end of the Isle of Man. Here, as in emphatically not the case with the Copepoda and other other localities which have been investigated, the Phyto-constituents of the plankton, and it was not the case even Plankton is found to increase greatly about the time of with the Diatoms during the succecding year. the vernal equinox, so as to cause a maximum, largely I have pubiished elsewhere an observation that showed composed of Diatoms, at a period ranging from the end of very definite limitation of a large swarm of crab Zoëas, so March to some time in May--this year to May 28, in the that none were present in one net while in another adjacent Irish Sea. Towards the end of this period the eggs of haul they multiplied several times the bulk of the catch most of the edible fishes are hatching as larvæ.

and introduced a new animal in enormous numbers. Had This Diatom maximum is followed by an increase in two expeditions taken samples that evening at what might the Copepoda (minute crustacea), which lasts for a con- well be considered as the same station, but a few hundred siderable time during the early summer, and as the fish yards apart, they might have arrived at very different conlarvæ and the Copepoda increase there is a rapid falling clusions as to the constitution of the plankton in that part off in Diatoms. Less marked maxima of both Diatoms of the ocean. and Copepoda may occur again about the time of the It is possible to obtain a great deal of interesting inautumnal equinox. These two groups—the Diatoms and formation in regard to the “hylokinesis" of the sea withthe Copepoda-are the most important economic con- out attempting a numerical accuracy which is not yet stituents in the plankton. A few examples showing their attainable. The details of measurement of catches and oi importance to man may be given :-Man eats the oyster computations of organisms become useless, and the exact and the American clam, and these shell-fish feed upon figures are non-significant, if the hauls from which they Diatoms. Man feeds upon the cod, which in its turn may are derived are not really comparable with one another and seed on the whiting, and that on the sprat, and the sprat the samples obtained are not adequately representative of on Copepoda, while the Copepoda feed upon Peridinians nature. If the stations are so far apart and the dates are and Diatoms; or the cod may feed upon crabs, which in so distant that the samples represent little more than turn eat

worms,

and these feed upon smaller forms themselves, if the observations are liable to be affected by which are nourished by the Diatoms. Or, again, man any incidental factor which does not apply to the entire eats the mackerel, which may feed upon young herring, area, then the results may be so erroneous as to be useless, and these upon Copepoda, and the Copepoda again upon or worse than useless, since they may lead to deceptive Diatoms. All such chains of food matters from the sea conclusions. It is obvious that we must make an intensive seem to bring one through the Copepoda to the Diatoms, study of small areas before we draw conclusions in regard which may be regarded as the ultimate" producers " of to relatively large regions, such as the North Sea or the food in the ocean. Thus our living food from the waters Atlantic Ocean. Our plankton methods

vet of the globe may be said to be the Diatoms and other accurate enough to permit of conclusions being drawn as microscopic organisms as much as the fishes.

to the number of any species in the sea. Two years ago, at the Leicester meeting of the British The factors causing the seasonal and other variations in Association, I showed that if an intensive study of a small the plankton already pointed out may be grouped under area be made, hauls being taken, not once a quarter or three heads, as follows :once a month, but at the rate of ten or twelve a day, (1) The sequence of the stages in the normal life-history abundant evidence will be obtained as to (1) variations in of the different organisms. the distribution of the organisms, and (2) irregularities (2) Irregularities introduced by the interactions of the in the action of the nets. Great care is necessary in order different organisms. to ensure that hauls intended for comparison are really (3) More or less periodic abnormalities in either time or comparable. Two years' additional work since in the same abundance caused by the physical changes in the sea, which locality, off the south end of the Isle of Man, has only may be grouped together as “ weather." confirmed these results, viz. that the plankton is liable to These are all obvious factors in the problem, and the be very unequally distributed over the depths, the localities, constitution of the plankton from time to time throughout and the dates. One net may encounter swarm of the year must be due to their interaction. The difficulty organisms which a neighbouring net escapes, and a sample is to disengage them from one another, so as to determine taken on one day may be very different in quantity from the action of each separately. a sample taken under the same conditions next day. If Amongst the physical conditions coming under the third an observer were to take quarterly, or even monthly, heading, the temperature of the sea is usually given a very samples of the plankton, he might obtain very different prominent place. There is only time to allude here to one results according to the date of his visit. For example, on aspect of this matter. three successive weeks about the end of September he It is often said that tropical and sub-tropical seas are might find evidence for as niany different far-reaching relatively poor in plankton, while the colder Polar regions views as to the composition of the plankton in that part are rich. In fishing plankton continuously across the of the Irish Sea. Consequently, hauls taken many miles Atlantic it is easy from the collections alone to tell when apart and repeated only at intervals of months can scarcely the ship passes from the warmer Gulf Stream area into give any sure foundation for calculations as to the popula- the colder Labrador current. This is the reverse of what tion of wide sea areas. It seems, from our present know- we find on land, where luxuriant vegetation and abundance ledge, that uniform hydrographic conditions do not deter- of animal life are characteristic of the tropics in contrast mine a uniform distribution of plankton.

to the bare and comparatively lifeless condition of the These conclusions need not lead us to be discouraged as Arctic regions. Brandt has made the ingenious suggestion to the ultimate success of scientific methods in solving that the explanation of this phenomenon is that the higher world-wide plankton and fisheries problems, but they temperature in tropical seas favours the action of denitriiv. suggest that it might be wise to secure by detailed local ing bacteria, which therefore flourish to such an extent in work a firm foundation upon which to build, and to ascer- tropical waters as seriously to diminish the supply of tain more accurately the representative value of our samples nitrogen food and so limit the production of plankton. before we base conclusions upon thein.

Loeb, on the other hand, has recently revived the view I do not doubt that in limited, circumscribed areas of of Murray, that the low temperature in Arctic waters so water, in the case of organisms that reproduce with great 1 " Darwin and Modern Science" (Cambr'dge, 1903), p. 247.

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reduces the rate of all metabolic processes, and increases tion in check must be equally astonishing. It is claimed the length of life, that we have in the more abundant that the Valdivia results, and observations made since, plankton of the colder waters several generations living on show that the most abundant plankton is where the surface side by side, whereas in the tropics with more rapid meta- water is mixed with deeper layers by rising currents. bolism they would have died and disappeared. The Nathansohn, while finding that the hour of the day has temperature of the sea-water, however, appears to have no effect on his results, considers that the development of little or no effect in determining the great vernal maximum the Phyto-Plankton corresponds closely with evidence of of Phyto-Plankton.

vertical circulation. Like

other workers,

he Considering the facts of photosynthesis, there is much to emphasises the necessity of continuous intensive work in be said in favour of the view that the development, and one locality : such work might well be carried on both at possibly also the larger movements of the plankton, are some point on your great lakes and also on your Atlantic influenced by the amount of sunlight, quite apart from any

The Challenger and other great exploring expeditemperature effect.

tions forty years ago opened up problems of oceanography, Bullen showed the correlation in 1903-7 between the but such work from vessels passing rapidly from place to mackerel catches in May and the amount of Copepod place could not solve our present problems—the future lies plankton in the same sea. The food of these Copepoda with the naturalists at biological stations working conhas been shown by Dakin to be largely Phyto-Plankton, tinuously in the same locality the year round. and Allen has lately 2 correlated the average mackerel The problems are most complex, and may vary in catch per boat in May with the hours of sunshine in different localities-for example, there seem to be two kinds the previous quarter

of the year,

thus establishing Diatom maxima found by Nathansohn in the M terthe following connection between the food of man and ranean, one of Chætoceros due to the afflux of water from the weather :-Mackerel-Copepoda--Diatoms-Sunshine. the coast, and one of Rhizosolenia calcaravis, due to a One more example of the influence of light may be given. | vertical circulation bringing up deeper layers of water. As Koloid has shown that the plankton of the Illinois River a local example of the importance of the Diatoms in the has certain twenty-nine-day pulses, which are apparently plankton to inan, let me remind you that they form the related to the lunar phases, the plankton maxima lagging main food of your very estimable American clam. The about six days behind the times of full moon. The light figures I now show, and some of the examples I am taking, from the sun is said to be 618,000 times as bright as that are from the excellent work done on your own coasts in from the full inoon; but the amount of solar energy connection with fisheries and plankton by Prof. Edward derived from the moon is sufficient, we are told, appreci- Prince and Prof. Ramsay Wright and their fellow-workers ably to affect photosynthesis in the Phyto-Plankton. The at the Canadian biological station, on your eastern seaeffectiveness of the moon in this photosynthesis to that of board. the sun is said to be as two to nine, and if that is so The same principles and series of facts could be illusKofoid is probably justified in his contention that at the trated from the inland waters. Your great lakes periodictime of full moon the additional light available has a ally show plankton maxima, which must be of vast importmarked effect

upon the development of the Phyto- ance in nourishing animals and eventually the fishes used Plankton.

by man. Your geologists have shown that Manitoba was As on land, so in the sea, all animals ultimately depend in post-Glacial times occupied by the vast lake Agassiz, upon plants for their food. The plants are the producers with an estimated area of 110,000 square miles; and while and the animals the consumers in nature, and the pastures

the sediments of the extinct lake form your celebrated of the sea, as Sir John Murray pointed out long ago, are wheat fields, supplying food to the nations, the shrunken no less real and no less necessary than those of the land. remains of the water still yield, it is said, the greatest Most of the fish which man uses as food spawn in the fresh-water fisheries in the world. See to that nothing sea at such a tiine that the young fry are hatched when

is done to reduce further this valuable source of food ! the spring Diatoms abound, and the Phyto-Plankton is Quoting from your neighbours to the south, we find that followed in summer by the Zoo-Plankton (such as Cope- the Illinois fisheries yield at the rate of a pound a day poda), upon which the rather larger but still immature throughout the year of cheap and desirable food to about food fishes subsist. Consequently, the cause of the great 80,000 people-equivalent to one meal of fish a day for a vernal maximum of Diatoms is one of the most practical quarter of a million people. of world problems, and many investigators have dealt with Your excellent “whitefish " alone has yielded, I see, it in recent years. Murray first suggested that the meadows in recent years more than 5,000,000 lb. in a year; and all of the sea, like the meadows of the land, start to grow

scientific men who have considered fishery questions will in spring simply as a result of the longer days and the note with approval that all your fishing operations are now notable increase in sunlight. Brandt has put forward the

carried on under regulations of the Dominion Government, view that the quantity of Phyto-Plankton in a given layer

and that fish hatcheries have been established on several of surface water is in direct relation to the quantity of of your great lakes, which will, along with the necessary nutritive matters dissolved in that layer. Thus the actual restrictions, form, it may be hoped, an effective safeguard quantity present of the substance-carbon, nitrogen, silica,

against depletion. Much still remains to be done, howor whatever it may be that is first used up determines ever, in the way of detailed investigation and scientific the quantity of the Phyto-Plankton. Nathansohn in a exploitation. The German institutes for pond-culture show recent paper' contends that what Brandt supposes never

what can be done by scientific methods to increase the really happens ; that the Phyto-Plankton never exhausts any

supply of food-fishes from fresh waters. It has been food constituent, and that it develops just such a rate of

shown in European seas that the mass of living food reproduction as will compensate for the destruction to

matters produced from the uncultivated water may equal which it is subjected. This destruction he holds is due that yielded by cultivated land. When aquiculture is as to two causes : currents carrying the Diatoms to unfavour

scientific as agriculture, your regulated and cultivated able zones or localities, and the animals of the plankton waters, both inland and marine, may prove to be which feed on them. The quantity of Phyto-Plankton pre

more productive even than the great wheat lands of sent in a sea will then depend upon the balancing of the

Manitoba. two antagonistic processes-the reproduction of the Diatoms

Inland waters may be put to many uses : sometimes they and their destruction. We still require to know their rate

are utilised as sewage outlets for great cities, sometimes of reproduction and the amount of the destruction. It they are converted into commercial highways, or they may has been calculated that one of these minute forms, less become restricted because of the reclamation of fertile than the head of a pin, dividing into two at its normal

bottom lands. All these may be good and necessary rate of five times in the day, would at the end of a month

developments, or any one of them may be obviously best form a mass of living matter a million times as big as the in the circumstances; but, in promoting such The destruction that keeps such a rate of reproduc- schemes, due regard should always be paid to the import

and promise of natural waters

perpetual 1 M. B. A. Journ., viii., 259.

2 Thiit., vii., 394.

source of cheap and healthful food for the people of the 3 Monaco Bulletin, No. 14).

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UNIVERSITY AND EDUCATIONAL

SOCIETIES AND ACADEMIES.
INTELLIGENCE,

Paris.
A NUMBER of resolutions concerned with education were

Academy of Sciences, September 6.-M. Bouchard in the adopted last week at the Trade Union Congress held at

chair.—The theoretical tides of the geoid, on the hypoIpswich. Some called for the State maintenance of school

thesis of an absolute rigidity of the earth : Ch. Lallemand, children, for scientific physical education, and the develop- Defining the geoïd as the surface mcan level confining ment of the medical department of the Board of Education.

a volume equal to that of the globe, the mean tides at Others demanded that secondary and technical education

the equator are worked out for both the solar and lunar be an integral part of every child's education, and be

waves.-The Brownian movement and molecular constants: secured by such a reform and extension of the scholarship Jean Perrin and M. Dabrowski. Experiments have been system as would place a maintenance scholarship within made on two emulsions of different substances containing the reach of every child, and thus make it possible for all

minute particles in suspension. The results are applied to children to be full-timne day pupils up to the age of sixteen ;

determine the constant N of Avogadro in Einstein's and that the best intellectual and technical training be formula, and also in a formula based on the distribution provided for the teachers of the children, that each educa

of the particles under the action of gravity. The forme: tional district be required to train the number of pupil | leads to a value of 70 x 10”, and the latter to 70-5 X 10*. teachers demanded by local needs and to establish training The close accord of these results is a striking confirmation colleges, preferably in connection with universities or

of the kinetic theory on which the formulæ are basád. university colleges. The interest in education thus manifested by the leaders of our working men may be regarded from these values is 4.1 X 10-10

The most probable value of the charge of the electrone

10.-Calorimetric and coas a gratifying sign of the times. All who desire the scopic constants of mercuric bromide : M. Guinchant welfare of the nation would welcome any real improvement The measured latent heat of fusion gives a cryoscopic rur: in our system of educating suitably the men upon whom the success of our industries largely depends; but many

stant according to van 't Hoff's formula of 403 i actua!

cryoscopic determinations in various solvents furnished a competent persons will doubt the wisdom of the great

constant of 283 to 407, the average value being 340.-The extension of our scholarship system demanded by the Trade life of fungi in fatty media : A. Roussy. For various Union Congress. In any system of awarding scholarships moulds it was found that fatty substances were capable of every care must be taken to ensure that each scholarship replacing carbohydrates in culture media.

The concentra. holder has shown by his previous record that he is mentally tions of fat most favourable for growth of the moulds were qualified to benefit by the secondary and technical educa- determined.-Some wild

yams of Madagascar : Herri tion which the scholarship makes possible, and will com- Jumelle and H. Perrier de la Bathie.-The experimental plete the course at the school. It is important to educate

transmission of exanthematic typhus by the bodv louse : every person to the full extent of his capabilities, but it

Charles Nicolle, C. Comte, and E. Conseil.—The géois folly to imagine that every boy or girl who is made to attend a technical school must of necessity be able to

logical structure of the peninsula of Cape Bon, Tunis:

A. Allemand-Martin. benefit from such attendance.

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The technical colleges throughout the country are now

CONTENTS.
issuing their programmes of work for the coming session.
We have received the educational announcements of the Principles of Igneous Petrology. By J. S. F.
Northampton Polytechnic Institute, Clerkenwell, the

A Popular Mammal Book By R. L. syllabus of classes at the Sir John Cass Technical' Insti- Applied Mechanics. By T. H. B. tute, Aldgate, London, and the prospectus of the East

A Belgian Botanist Ham Technical College evening classes. The educational

Our Book Shelf:aim of the Northampton Institute is to provide classes in

Symington and Rankin : “An Atlas of Skiagrams, technological and trade subjects, attention being first paid

illustrating the Development of the Teeth, with to the immediate requirements of Clerkenwell, the district

Explanatory Text" of London in which the institute stands. The day courses

Frey: "Mineralogie und Geologie für schweizerische are for students willing to give the whole of their time

Mittelschulen."-G. A. J. C. for one, two, or more years to a systematic training in

Shelley: “Gilbert White and Selborne technologi. Day courses are provided in mechanical

Lotters to the Editor :engineering, electrical engineering, watch-making, and

The Summer Season of 1909. (IVith Diagram.) horological engineering. In horology, a very large amount

Alex. B. MacDowall of time is given to workshop practice. There are also

A New Mineral from a Gold-washing Locality in the day courses in technical optics, electrochemistry, and other

Ural Mountains.-P. Walther. subjects. Evening classes are held in a very great variety

The Benham Top.-Charles E. Benham of subjects. At the Aldgate institution graded courses of

The Approaching Opposition of Mars. (Illustrated.) study extending over several years are provided in the

By William E. Rolston various departments, and also special lectures, with

Polar Expeditions and Observations accompanying laboratory practice, are given to meet the

Chemistry in the Service of the State. By C. S. needs of persons holding responsible positions in the manu

The British Association at Winnipeg facturing establishments in the neighbourhood who desire Section G.-Engineering.-Opening Address by Sir to keep in touch with modern developments in applied

W. H. White, K.C.B., Sc.D., LL.D., F.R.S., science. Among the announcements of such special work

President of the Section may be mentioned the course on liquid, gaseous, and solid

Notes. (Illustrated.) fuel arranged for the benefit of workers in chemical and

Our Astronomical Column: engineering establishments and others concerned with the Halley's Comet Re-discovered use of fuel as a motive power; that on the fermentation

Observations of Mars industries, with particular attention to microbiology; and

A Large Group of Sun-spots that concerned with metallurgical problems. The evening

The Transvaal Observatory classes at East Ham are under the general supervision of

Artificial Imitation of Lunar Landscape a responsible principal, and it is consequently possible for Temperature and Pressure Conditions in the Solar a student to obtain advice in the direction of securing a Atmosphere properly coordinated course of study continuing from year

Parallax of the Double Star 3 2398 to year. The numerous classes are adapted particularly

Our Food from the Waters. By Prof. w. a. meet the requirements of young men and

Herdman, F.R.S. engaged in the manual and other industrial trades of the University and Educational Intelligence locality.

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Societies and Academies

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