may best be exhibited so as to satisfy all the purposes for which they are intended. M. Felix Plateau, at a former meeting, proposed to substitute yellow for colourless glass in lighting rooms containing entomological collections. In the discussion which followed it was suggested that experiments should be made by submitting insects to the influence of glasses of various colours. M. Capronnier was entrusted with carrying out these experiments, and the paper referred to contains his report.

Everyone knows that among the Lepidoptera it is the green and carmine colours which are most rapidly destroyed by daylight. M. Capronnier wished to obtain insects of the year's hatching, but could only obtain sufficient quantities of Euchelia Jacobæa, L. The inferior wings of this insect are of a deep carmine, uniform in tone, an important point in the experiments.

The principal colours of the solar spectrum are the yellow, the red, the blue. M. Capronnier rejected the red as giving a tint too dark, and added the mixed colours, violet and green. He had thus four tints chosen with the same degree of tone, and of a moderate shade— yellow, violet, green, and blue, besides a colourless glass. He made five small square boxes of 08 centimetres square and one centimetre in depth; the whole surface was covered with one of the above-mentioned glasses.

Each wing was fixed in the middle of the box and floated in a bath of very bright light, but protected from the rays of the sun. Each of the wings was partly covered by a band of black paper, and their position was so arranged as to leave exposed successively each of the parts during a period of fifteen, thirty, and ninety days. The following are the results :

Colourless glass.-After fifteen days of exposure the carmine tint was visibly attacked. After thirty days the alteration was more sensible, and after ninety days the work of destruction had rapidly advanced, and the carmine had passed into a yellowish tint.

Blue. With this tint the same alterations took place as in the case of colourless glass.

Green. This colour preserved the carmine during the first fifteen days; a change was indicated on the thirtieth day, and on the nintieth the alteration was marked.

Yellow. During the ninety days the yellow alone left the carmine colour almost intact. M. Capronnier says almost, for a slight alteration in the tint could be noticed at the end of the ninety days. This last observation proves that there is no absolute preservative, and that collections must be kept in darkness, under penalty of seeing them seriously changed at the end of a given time.

Nevertheless, it is evident from the above that the yellow is the best preservative against alterations in the colours of insects. M. Capronnier consequently concludes that a yellowish colour should be preferred and combined in every arrangement of an entomological room. Moreover the cloths that cover the show-cases ought to be yellow rather than green, and what is important and indispensable, the window-blinds ought to be absolutely yellow.

RADIOMETERS1

DURING the discussion which followed the reading of Prof. Reynolds's and Dr. Schuster's papers at the last meeting of the Royal Society I mentioned an experiment bearing on the observations of Dr. Schuster. I have since tried this in a form; and as the results are very decided and appear calculated to throw light on many disputed points in the theory of these obscure actions, I venture to bring a description of the experiment, and to show the apparatus at work, before the Society.

I made use of a radiometer described in a paper com"On the Movement of the Glass Case of a Radiometer." By William Crookes, F.R.S., &c. Read at the Royal Society.

municated to the Society in January last. I quote the description from paragraph 184. "A large radiometer in a 4-inch bulb was made with ten arms, eight of them being of brass, and the other two being a long watch-spring magnet. The discs were of pith, blackened on one side. The power of the earth on the magnet is too great to allow the arms to be set in rotation unless a candle is brought near, but once started it will continue to revolve with the light some distance off."

This radiometer was floated in a vessel of water and four candles were placed round it, so as to set the arms in rotation. A mark was put on the glass envelope so as to enable a slight movement of rotation to be seen. The envelope turned very slowly a few degrees in one direction, then stopped and turned a few degrees the opposite way; finally it took up a uniform but excessively slow movement in the direction of the arms, but so slow that more than an hour would be occupied in one revolution.

A powerful magnet was now brought near the moving arms. They immediately stopped, and at the same time the glass envelope commenced to revolve in the opposite direction to that in which the arms had been revolving. The movement kept up as long as the candles were burning, and the speed was one revolution in two minutes.

The magnet was removed, the arms obeyed the force of radiation from the candles, and revolved rapidly, whilst the glass envelope quickly came to rest and then rotated very slowly the same way as the arms went.

The candles were blown out; and as soon as the whole instrument had come to rest, a bar-magnet was moved alternately from one side to the other of the radiometer, so as to cause the vanes to rotate as if they had been under the influence of a candle. The glass envelope moved with some rapidity (about one revolution in three minutes) in the direction the arms were moving. On reversing the direction of movement of the arms the glass envelope changed direction also.

These experiments show that the internal friction, either of the steel point on the glass socket, of the vanes against the residual air, or of both these causes combined, is considerable. Moving the vanes round by the exterior magnet carries the whole envelope round in opposition to the friction of the water against the glass.

As there is much discussion at present respecting the cause of these movements, and as some misunderstanding seems to prevail as to my own views on the theory of the repulsion resulting from radiation, I wish to take this opportunity of removing the impression that I hold opinions which are in antagonism to some strongly urged explanations of these actions. I have on five or six occasions specially stated that I wish to keep free from theories. During my four years' work on this subject I have accumulated a large fund of experimental observations, and these often enable me to see difficulties which could not be expected to occur to an investigator who has had but a limited experience with the working of one or two instruments.

COMPRESSED AIR LOCOMOTIVE USED IN THE ST. GOTHARD TUNNEL WORKS1 THE HE boring of a tunnel of any importance presents difficulties of various kinds, among which may be mentioned the clearing away of the rubbish arising from the excavation of the gallery, whenever that reaches any considerable length, and the work is carried on with activity. Such were the conditions under which the boring of the Mont Cenis tunnel was carried on, and M. Fabre, the able contractor, has met with similar difficulties in the boring of the St. Gothard tunnel, now being carried out.

From an article in La Nature, by M. C. M. Gariel.

these machines would allow only pure air to escape; and then these motors would be more powerful than horses, and effect more rapidly the clearing away of the débris. A first attempt was made in which two ordinary locomotives were employed, one at each side of the tunnel; the boilers, in which, of course, there was no water, were filled with condensed air under a pressure of four atmospheres. This air played the part usually done by steam, passed into slide valves, entered the cylinders alternately on each face of the pistons, which it set in motion, and then escaped into the atmosphere.

N B

It is easily seen that if compressed air were to be employed, it would be indispensable to have a very considerable quantity of it; the boiler of a locomotive, sufficient when it is worked by means of steam constantly produced under the action of heat, was too small to contain a quantity of air sufficient for use without being filled. This led to adding to each locomotive a special reservoir for compressed air; each locomotive was accompanied, as a kind of tender, by a long sheet-iron cylinder, 8 metres long and 1 metres diameter, supported towards its extremities by two trucks, which, on starting, were filled with condensed air, and which communicated by a tube with the distributing apparatus of the cylinders. The locomotive then worked as before, except that compressed air came from the reservoirs instead of from the boiler. The two locomotives, the Reuss and the Tessin, worked economically for about two years, in spite of the

awkwardness of the long cylinders that accompanied them. We can give some interesting figures resulting from the mean of a certain number of observations. At departure the pressure in the reservoir was about 7 kilogrammes per square centimetre; the locomotive having drawn a train of twelve loaded waggons along a course of about 600 metres, the pressure was found to fall to 4 kilogrammes; the train then returned empty to the point of departure, and the final pressure was found to be 2 kilogrammes.

In spite of the relatively advantageous results which were obtained, the employment of compressed air in a steam locomotive presented a certain number of drawbacks. It is expedient that the air should issue from the cylinder under the least possible pressure, in order that refrigeration may be reduced to a minimum; for it is known that the expansion of gas is accompanied by a loss of heat which increases with the pressure. This condition was satisfied by causing the air to act under restraint; that is, by allowing the compressed air coming

from the reservoir to enter during only a part of the course of the piston. But the admission of the air ought to vary if it is desired to obtain the same final effect, since the pressure in the reservoir diminishes continuously; and as the apparatus which regulates the admission was arranged to correspond only to determined fractions, but not to vary in a continuous manner, it followed that there was a greater expenditure of air than was necessary, and consequently a diminution in the length of the course over which the locomotive could run. On the other hand it is necessary that the air should arrive in the distributing apparatus with the least possible pressure, for it is in this apparatus, in the slide-value, that the greatest losses take place, and these losses increase in proportion to the pressure. No means could, however, be thought of for diminishing the pressure in the reservoirs, which would have reduced considerably the work which the machines were capable of doing, unless by augmenting considerably the volume of the reservoirs, the dimensions of which were already unusually large.

At this stage M. Ribourt, the engineer of the tunnel, devised an arrangement which allows the compressed gas to flow at a fixed pressure whatever may be the pressure in the reservoir. The gas in escaping from the reservoir enters a cylinder B (Fig. 1), over a certain extent of the walls of which are openings mm, that communicate with another cylinder C, which surrounds it to the same extent, and which is connected with the slidevalve by which the air is distributed, or, more generally, with the space in which this air is to be utilised. On one side moves a piston E, which shuts the cylinder and hinders the escape of the air. This piston carries externally a shaft F, which supports externally a spiral spring H, the force of which is regulated by means of a screw. Internally it is connected by another shaft L with a second piston N, which bears a cylinder M, movable in the interior of the principal pump, and forming thus a sort of internal sheath. This sheath presents openings nn, which may coincide exactly with those already referred to, and in that case the gas passes without difficulty from the reservoir at the point where it is to be employed. But if the sheath is displaced, the openings no longer correspond, there is resistance to the passage, and consequently diminution of the quantity of gas which flows out, and hence lowering of pressure in the exterior cylinder. By making the position of the sheath to vary continuously we may make the pressure of exit constant, notwithstanding the continuous variation at entry. But the apparatus is automatic. In fact the part of the cylinder B comprised between the bottom and the piston N communicates by openings (which are never covered with the escape-tube of the gas), in such a manner that upon its posterior face the piston N receives the pressure of the gas at the moment when it flows, a pressure which it is sought to render constant. The piston E receives on its anterior face the action of the spring which can be regulated at pleasure. As to the other faces of the two pistons, they are subjected to equal actions proceeding from the pressure of the gas at its entry, actions which thus counteract each other; so that the forces which determine the position of the movable system are on the one hand the tension of the spring, a constant and determined force, and on the other hand, the pressure of the flowing gas; and thus equilibrium cannot occur unless the two forces are equal. If the gas should flow in too great quantity, the pressure increases on the posterior face of the piston N, the spring is overcome, and the movable system advances a little towards the left; but then the orifices are partly covered and the flow diminishes. If the pressure then becomes too weak at the exit, the spring in its turn prevails, pushes the sheath towards the right, uncovers the orifices, and consequently a greater quantity of air may enter.

The machines which are now used at the St. Gothard tunnel, genuine compressed air locomotives, are furnished with M. Ribourt's apparatus. They consist of the following parts :-A sheet-iron reservoir to contain the compressed air is mounted on a framework quite like that of steam locomotives, and carrying glasses, cylinders, distributing apparatus, &c. The tube for receiving the air possesses, within reach of the driver, the automatic valve of M. Ribourt. The screw being easily regulated, the air can with certainty be made to issue from the apparatus at a determined pressure. This air then passes into a small reservoir (about one-third metre cube) intended to deaden the shocks, which are always produced when the machine is set agoing or stopped. Lastly, this small reservoir communicates with the cylinders, and the air which reaches them acts in the same manner as steam in ordinary locomotives.

The pressure in the principal reservoir at the point of exit depends on the power of the compressing apparatus; at St. Gothard it may attain 14 kilogrammes per square centimetre, but is ordinarily about 7'35 kilogrammes. The pressure in the small reservoir is arbitrary, depending on the regulation of the screw; at St. Gothard it has a mean of 4'20 kilograır.mes. The entire machine weighs about 7 tons.

THE

PHYSICAL SCIENCE IN SCHOOLS

HE passages from Mr. Wilson's essay of 1867 and his letter of 1876 appeared to me in contradiction on the value of science in developing the power of reasoning and of language, since in his letter Mr. Wilson says that science should not be taught to boys till they have attained a certain power of reasoning and language as shown by their attainments in geometry and Latin; and in his Essay he speaks of science as supplying the want of clearness and certitude better than arithmetic or geometry, and again, as of all processes of reasoning the exhaustive illustration; and I wished to know whether Mr. Wilson had altered his opinion in the last ten years on this point.

The question at issue is as stated: "Given that boys are going to remain under a system of liberal education till eighteen or nineteen, at what stages is it shown by experience that it is wise to introduce the different sciences?" Certainly my experience has not been so extensive as Mr. Wilson's, but I possess the qualification he demands for forming an opinion, that while (during eight years) I have taught science I have also at various times been occupied with mathematics and with language

The extent to which science should be introduced into the curriculum of a particular school, and the order in which the various subjects should be taken up, cannot, I think, be practically determined without taking into account various points of mere expediency. If, for example, expense were no consideration, I should prefer certain branches of physics, for example, magnetism and electricity, as the subjects for the first practical work to be undertaken rather than chemistry. But practically there is this difference, that a class of twenty or thirty boys in practical chemistry can be handled by one master with fair success; whereas the attempt to carry a class through any such course of physics as that sketched in Weinhold (translated by Foster) could, I think, only end in failure. Two or three boys to whom one master could give his whole attention might use the book with advantage, but a class could not be so handled, except at the additional cost of two or three assistants and considerable time for preparation.

Without, then, asserting that this is the plan theoretically best, we have been led by circumstances at Giggleswick into the following course :

The school is divided into the upper school, and the lower (or preparatory) school; the upper school consists

of five classes. No science work (at present) is done in the preparatory school, but all boys in the upper school do some. With the lowest class the subjects are physical geography, and in the summer, botany.

The two reasons why science should be taught in schools are (to quote from Mr. Wilson) that it "is the best teacher of accurate, acute, and exhaustive observation of what is," and that "of all processes of reasoning it stands alone as the exhaustive illustration." And the teaching of physical geography and botany I regard as fulfilling the first of these purposes. We enjoy unusual advantages for the study of these two subjects in the nature of the surrounding country. We are upon the millstone grit, but only a few hundred yards from the great Craven Fault, where the mountain limestone is elevated some 800 feet above the grit into the Giggleswick Scar. At the distance of a few miles we have the limestone and Yoredale rocks resting unconformably upon the vertical Silurian rocks. Traces of glacial action are numerous-the new line from Settle to Carlisle cuts through moraines, where scratched pebbles may be picked up by the dozen. Erratic blocks are scattered thickly over the whole country. At hand we have the Victoria Cave, and the remains it has yielded are preserved in the school museum, and we are within an afternoon's ramble of the summits of Ingleborough and Penyghent, and of Clapham Cave, and numerous others. We are equally well off in the matter of botany; a radius of six miles round the school probably includes a greater variety of plants than any equal area in England.

Supposing a boy to enter the upper school at the age of twelve, he would perhaps remain in the class for a year, and at the age of thirteen would enter upon the systematic study of science; and his first subject would be chemistry, which he would attack at once practically. Four hours a week are given in this class to the study of chemistry a practical lesson of two hours and two oral lessons of an hour each. In the class of perhaps twenty-five, all the boys are making the same experiments at the same time, and the work consists mainly in the study of the properties of the salts of particular metals. The boys are led to infer for themselves from their own experiments the solubility or insolubility of the salts of the metals in water, acids, &c., and from that to advance to simple analysis. No text-book is used.

In the oral lessons we advance very slowly; one term suffices probably to get through not more than oxygen, hydrogen, and water, and perhaps to begin air. It seems to me that a boy learns much more by understanding thoroughly the experimental evidence that nine pounds of water contain eight pounds of oxygen, than in learning "the "mode of preparation and properties" of the oxides of nitrogen and a dozen other substances. In the next class in which the average age is perhaps fourteen to fifteen, we get through nitrogen, carbon, chlorine, bromine, iodine, fluorine, and perhaps sulphur, practical work being continued at the same rate as before. In the second class we have two hours a week for chemistry, two hours for practical work, and two hours for physics. In physics we take the various branches in succession, and get through the subjects of Balfour Stewart's "Physics" in about two years, which is the time many boys remain in the class, the ages being fifteen to seventeen. In the first class we have eight hours a week. The subjects we are taking at present are:- Inorganic and Organic Chemistry, two hours; Analysis, two hours; Electricity and Magnetism, two hours; Astronomy, two

hours.

We shall shortly be able, in consequence of the extension of the buildings, to add some practical work in physics. But this will be only for the highest class.

Will you allow me, in conclusion, to quote some of the conclusions of the British Association Committee on Scientific Education in Schools, which appear to me to

be still as important as when they were first written. The Committee included Mr. Farrar, Prof. Huxley, Prof. Tyndall, and Mr. Wilson:

"There is an important distinction between scientific information and scientific training; in other words, between general literary acquaintance with scientific facts, and the knowledge of methods that may be gained by studying the facts at first hand under the guidance of a competent teacher." Both of these are valuable; it is very desirable, for example, that boys should have some general information about the ordinary phenomena of nature, such as the simple facts of astronomy, of geology, of physical geography, and of elementary physiology. On the other hand, the scientific habit of mind, which is the principal benefit resulting from scientific training, and which is of incalculable value, whatever be the pursuits of after-life, can better be attained by a thorough knowledge of the facts and principles of one science than by a general acquaintance with what has been said and written about many.

"The subjects we recommend for scientific information should comprehend a general description of the solar system, of the form and physical geography of the earth, and of such natural phenomena as tides, currents, winds, and the causes that influence climate, of the broad facts of geology, of elementary natural history with especial reference to the useful plants and animals. And for scientific training we are decidedly of opinion that the subjects which have paramount claims are experimental physics, elementary chemistry, and botany. The science of experimental physics deals with subjects which come within the range of every boy's experience. It embraces the phenomena and laws of light, heat, sound, electricity, and magnetism, the elements of mechanics, and the mechanical properties of liquids and gases. The thorough knowledge of these subjects includes the practical mastery of the apparatus employed in their investigation. The study of experimental physics involves the observation and colligation of facts, and the discovery and application of principles. It is both inductive and deductive. It exercises the attention and the memory, but makes both of them subservient to an intellectual discipline higher than either. The teacher can so present his facts as to make them suggest the principles which underlie them and which once in possession of the principle, the learner may be stimulated to deduce from it results which lie beyond the bounds of his experience. The subsequent verification of his deduction by experiment never fails to excite his interest and awaken his delight.

"Chemistry is remarkable for the comprehensive character of the training which it affords. Not only does it exercise the memory and the reasoning powers, but it also teaches the student to gather by his own experiments and observations the facts upon which to reason.

"Of the value of the elementary teaching in chemistry (at Rugby) there can be only one opinion. It is felt to be a new era in a boy's mental progress when he has realised the laws that regulate chemical combination and sees traces of order among the seeming endless variety. But the number of boys who get real hold of chemistry from lectures alone is small, as might be expected from the nature of the subject." W. MARSHALL WATTS

Giggleswick, April 15

We teachers must keep clear in our minds the two sides of the question: the relative educational value of the subject to be taught, and the age or capacity of the pupil. We may roughly classify sciences into those which cultivate the observing, and those which benefit the reasoning powers, though of course all sciences do both to some extent. Of the former, the only one which should be adopted systematically, in my opinion, is botany. Zoology cannot be as practically taught, though the habits of all kinds of animals afford infinite opportunity

for training the observing powers of pupils in the country; which should be judiciously directed by the teacher so as to render the observations continuous and systematic as far as they go; they should be always duly recorded, dated, and correctly described. But the encouragement of making collections must be done cautiously, as boys are too prone to be thoughtlessly cruel. Of course information on animals may be given informally. With regard to botany nearly twenty years' experience of teaching boys and girls of all ages and of nearly all classes, has convinced me that it may be commenced as soon as one likes. The plan pursued by my father at Hitcham (of which an account will be found in the Leisure Hour for 1862, p. 676) clearly proved the advantage to be derived by village school children, and I can corroborate it by my own attempts in another village; for there was a marked increase in the general intelligence, to say nothing of botany giving the children an amusing and instructive employment in the fields instead of their idling in the street-a fact noticed and strongly approved of by their parents. This subject, whatever may be the objections to others, can be taught to almost infants.

With regard to electricity, magnetism, and the elements of chemistry, beyond the last of these, I have no experience, but should fancy that the manipulation required would be unattainable before the ages of eleven or twelve, and the abstract nature of force would scarcely commend itself to the understanding before that age.

Physical geography, however, is another subject which, although affording less scope for the observing powers as botany, is by no means absolutely wanting in this respect. I cannot say that my "young boys [were] more (or less) attentive, active-minded, diligent when they [were] doing arithmetic than when they [were] at a lesson on physical geography." One principle I would insist upon is to appeal to the eye, as well as or rather more than the imagination, of young people. Hence in teaching this science, where no direct observation of the facts is possible (as of glaciers, in Warwickshire), my plan was to procure abundant and good illustrations, while the chief facts connected with their motions and formations would be illustrated by diagrams on the black board. Yet the effects of river and atmospheric action may be actually seen, often to a considerable extent, everywhere; and marine action having been learnt and understood at school, has been eagerly looked for when a visit to the sea-side was forthcoming. Here, however, not only facts should be taught, but their causes, or forces in action which have produced them, and the study will then never be dry. Physical geography has its value in realising in the pupil's mind the true nature of sequences between cause and effect, and he thus begins to grasp the fundamental principle of philosophy or "continuity" of action. I have found boys of eight thoroughly able to appreciate the elements of the subject; of course by adapting the facts and reasoning to their capacities.

Physical geography, being simply "modern geology," should invariably precede geology, which above all subjects cultivates inductive reasoning, and I have found boys from about twelve well able to grasp the main facts and reasonings. If they happen to be near any fossiliferous strata or where a variety of rock specimens may be procured, the encouragement to collect as many as possible should be given at any preceding age, for the most fascinating pursuit in science is undoubtedly collecting. (I have to this day crag shells collected at the age of eight, when I was first initiated into geological mysteries.) Collecting, however, is of course only the preliminary stage, and one's scientific lore must not be

allowed to rest there.

Before twelve I agree with Mr. Wilson that practical chemistry should not begin for reasons already mentioned. But, however, Mr. Wilson says, "Science should be introduced into a school, beginning at the top

and going downwards gradually to a point which will be indicated by experience," surely this is inverting a fundamental principle of education, and we may ask why should science be thus singled out? Why not begin at the top with Latin and arithmetic, and work downwards? Science, however, has its "elements" and its "advanced" stages like everything else. The sound est method seems to me to select the science for each age or capacity of pupils, and for the teacher himself to adapt the branch selected to them. Let him begin with botany-with children of the age of six, if he pleasesand by using the schedule he will find it almost selfadapting to the child's powers, as I have more fully explained elsewhere (see a paper "On the Practical Teaching of Natural Science in Schools," Educational Times, March 1, 1876). Physical geography might come next with pupils from eight to twelve, then the experimental sciences or geology from twelve upwards. The observing of the habits of animals might go along with any other science as an out-door instructive amusement, and be limited to no age.

Mr. Wilson talks of the difficulty of a "bored and weary schoolmaster teaching science informally." Passing by the fact that if he be bored and weary, it is largely due to his own want of interest in teaching or in engaging that of his pupils; I would maintain just the opposite opinion, that assuming a teacher to be such, informal teaching in natural history has a wonderful invigorating effect and re-awakens the attention which may have become dull by monotony. Thus I have often found during a lesson in Latin, e.g., Virgil's "Georgics," passages to be constantly occurring when "collateral science" can be invoked. And what is a proof of its value is, that it becomes suggestive to the pupils themselves, so that I have been obliged to check the superabundance of questions lest a Latin lesson should resolve itself into one on natural history.

Beyond such informal teaching as this I would never encourage it as a principle for teachers solely to act upon, with young children, though, of course there need be no restrictions in giving it them; but if science is to be taught at all-and all such informal methods are not really teaching-let it be thorough as far as it goes, lest it should lapse into a slipshod informality. It is the charm of the schedule system of botany that it demands close and accurate observation in the dissections, and the writing compels accuracy in the result as well as impresses the facts firmly upon the mem ry. Mr. Wilson is doubtless right in laying stress upon the necessity of securing abundance of capable teachers, which will probably ever be one of the chief difficulties to contend against. GEORGE HENSLOW

NOTES

M. LEVERRIER has sent to M. Waddington, the French Minister of Public Instruction, a proposal for the immediate construction of the great refractor for the Paris Observatory, which is to be finished in two years and five months. A tender has been sent to M. Leverrier by M. Eichens, the constructor of the great reflector, for that purpose; M. Leverrier proposes the acceptance of M. Eichens' offer.

M. LEVERRIER has been appointed president of the Scientific Committee of the Assemblée des Sociétés Savantes, which is to be held at the Sorbonne next week.

AN Academy of Science has been established at Kansas City,

Mo., United States, with appropriate sections for geology, zoology, botany, local history, numismatics, &c. One of the chief objects of the association is to form a museum of specimens which will represent the minerals and fossils, and the fauna and flora of Missouri, Kansas, and the territories.

FROM a communication received by the Scottish Meteorolo gical Society from their observer at Stykkisholm, Iceland, dated