Ο

current of air which but for them would be continuous; it is the vibrations of the air, and not of the reed, which produce a musical sound. When reeds are attached to organ-pipes, if stiff they rule the air-column, if flexible they are ruled by the air.

organ pipes.

In fig. 33 is shown an organ-pipe with one of its sides removed in order that its inner parts may be seen. The pipe is Construction of made to speak by driving the air up the tube t, which communicates with the wind-chest, into the chamber C, the top of which has a narrow outlet, ed, to the pipe P. Only a thin sheet of compressed air can pass through e d, and this then strikes upon the sharp edge, a b, causing a flutter; by the resonance of the pipe the proper pulse of this flutter is raised to a musical sound, and

-a b

the pipe "speaks." Fig. 34 represents an organ-pipe with a reed attached. A conical pipe, A B, surmounts the reed, and pressing against the latter is a wire, wi, which is employed to lengthen or shorten it. The clarionet is a reed pipe; a flute is an open pipe; in the hautboy and bassoon there are two reeds inclined at an angle to each other, and having a slit between them through which the air is forced. The human voice apparatus is a reed instrument; but for a description of this wonderful piece of Nature's mechanism we must refer our readers to the chapters upon Anatomy in the UNIVERSAL INSTRUCTOR.

When two notes of any instrument very close in pitch to each other are sounded together, there is heard an alBeats. ternate strengthening and enfeeblement of the sound, which produce what are ed known as "beats." These may be illustrated in various ways. If a note of the piano and its sharp or flat be sounded together beats are distinctly heard ; if the same notes are simultaneously sounded on different instruments which are not quite in tune, beats will be heard; if of two tuning-forks which are in unison one be loaded by putting a small piece of wax upon one of the prongs, they will, when sounded together, produce beats.

FIG. 33.

What is the cause of these beats? The

733

answer to this question may be obtained by considering briefly what happens Interference. very frequently in every pond or pool. If a stone be thrown into a pond, as is well known, it produces a series of circular waves, which spread out in a succession of concentric waves, which get fainter and fainter as they reach the margin of the pool. Let us suppose, instead of one such stone being thrown in, that two are dropped at a short distance from each other into the pond. Two sets of circular waves will thus be generated, and, if sufficiently close together, part of one set will interfere with part of the other set. In order to understand thoroughly the nature of this interference we must bear clearly in mind the exact nature of wavemotion. To any one standing on the beach and watching the billows as they roll in towards the shore, it is natural to suppose that there is an actual motion of translation in the water itself, and that not merely the wave, but the water itself, travels from the distant horizon and topples over at one's feet. It must, however, be clearly understood that the only motion of the particles of water is one in a vertical direction, each particle being first raised above and then sinking below the average level, and after thus oscillating for a few moments, subsiding to rest; the form of the wave travels, not the surface of the water over which it passes. The last portion of water topples over at our feet, because it has no other water to which it can impart the impulseit receives.

A

B

C

FIG. 34.

in general, it will be seen that if two sets of adjacent waves start simultaneously (each having the wave length), the interfering segments of each set will coincide with each other, and the result will be a dou

bling of the disturbance of the water. In fig. 35 the series of waves would obviously coalesce, the crests a b c d of A coinciding with the crests a'b'' d' of B. But if, as in B and C, one series of waves be half a wave length behind the other, it is equally obvious that the crests of one set will coincide with the sinuses of the other set; in the first case the two sets of waves will coalesce and produce waves of double height, while in the second case the waves will be antagonistic to each other, and tend to move the particles of water in opposite directions, at the same time destroying each other's motion, and equilibrium will be established-that is, no motion of the water will result. A little consideration will show that if one set of waves be any number of whole wave lengths, or any even number of half wave lengths behind the other, the two sets will coincide, but if one set be any odd number of half wave lengths behind, they will oppose each other. What has been said with regard to water waves applies precisely to sound waves. If two sets of sound waves are perfectly synchronous, a strengthening of the sound is produced; if one set differs from the other by any odd number of half wave lengths, they interfere, and either partially or totally destroy each other, and thus by adding sound to sound silence may result. It is, of course, easy to see that two sets of waves may be so related as sometimes to coincide with, at other times to oppose, each other, and so produce the phenomena of beats.

THE FRIENDLY COUNSELLOR.

EDUCATION FOR YOUNG WOMEN.

II.

COLLEGES FOR WOMEN-EXAMINATIONS FOR

WOMEN.

WE have hitherto spoken of work which girls may do at home, and of the mode of private study, but of course it is better to have instruction from one who has already gone over the ground. The teacher is a book that can be questioned, and in this undoubtedly lies the strong point of teaching. Care, however, must be taken not to fall into the error of imagining that a teacher should, so to speak, pour knowledge into you while you do nothing but respectfully assume the attitude of a receiving vessel. The best teacher in the world cannot educate a scholar who does not work and think and is not thoroughly in earnest. A teacher should, at any rate at the age at which a girl usually leaves school, be but a help and a guide in the efforts made by the student.

All work should be as diligently performed as if no teacher were expected to lend a helping hand later on. Do not rely on the tutor as a prop, or as a substitute for yourself; and while receiving instruction on a subject, do not omit

to revise the work already done, otherwise t impossible to make sure of gaining solid enduring advantage.

Of the kinds of teaching, that given to a class is the most beneficial, for the nat emulation which arises is a useful stimu exertion; and much is to be learnt from t. correction of the mistakes made by othas well as ourselves. Undoubtedly, how. some timid students who fear to face the * of a class would gain ground better private instruction. This can often be obtaine at a moderate cost.

Of late years numerous "corresponde". classes" have been formed, which have pr exceedingly useful to country students 7. have had no opportunity of attending case or lectures, and to whom private instra may have been equally unattainable. At undertakes the guidance of the studert ma particular subject or subjects, usually hay.. reference to some examination, and sc instructions as to the course of reas quisite; and the pupil may write to a tutt advice in cases of difficulty. Questions are re larly forwarded to be answered by the sun who receives them again corrected by the test Thus it is possible to estimate the progress the is being made, to a considerable extent.

An excellent system of corresponde maintained in connection with Newnham lege, Cambridge; this course is especialy tended to promote the self-education of waz and to assist them in preparing for the H Local examination of the University. Th mentioned as one out of a number of ex arrangements now practicable, by which the who are at a distance may not feel theme cut off from help. A little inquiry, and va sulting the advertising columns of the and daily journals will usually give the sta the opportunity of choosing that med struction which she thinks most suitable 1own particular case.

In nearly all large towns at the prevent a either there are colleges established on a manent foundation, or there are corres lectures given on important subjects of etion under the guidance of local cor and in connection with the great Universt Almost all the classes are open to wom 2.5 very many deal with subjects most destra women to study. Usually there is a le once a week on a definite subject, and aca follows it, at which questions are ask the written answers to previous quests discussed and criticised."

There are few who cannot afford keep up with at least one class, and it is while to make a struggle to gain such tion. Do not be deterred by the fact that requires an hour's walk to get to the hall, or that you may have no comp your own circle who cares to pursue the course. Very likely your example may some friend at a future time, if not now t about the task of self-improvement. Ins to be discouraged if you seem to make progress at first. All the time you ar spend fruitlessly is occupied with learning b

to study, which in itself is no insignificant acquirement. By all means regularly answer questious which are set: even though you may be able to do very little in that way, a little will soon become more, and you will feel pleasure instead of vexation, a sense of victory instead of one of discomfiture, when you discover that you have a real grasp and comprehension of a subject which was previously unknown to you.

Another valuable means of instruction open to women is afforded by the Science and Art classes now spread throughout the country in connection with the Government Department of Science and Art at South Kensington. In these classes continuous instruction is provided, by which many subjects in succession can be mastered, and the fees payable are within the reach of all.

A girl need not feel herself obliged to enter for a formal examination because she attends lectures or classes; and some no doubt educate themselves without the stimulus an examination affords. At the same time, where a girl has opportunity combined with good health, it is advisable to go in for some examination. She may not pass, and yet may gain great benefit from being examined. Some, no doubt, have not the natural qualifications for examination; they have not the coolness and selfpossession so necessary to the examinee. They may know their subjects, and yet be unable to reproduce their knowledge in an examination hall. These need hardly trouble about examinations. But no doubt those girls who may have to earn their own living should try and pass something; and what girls are sure that fortune will always smile upon them and prevent their ever having to battle with the world for themselves? A girl cannot now-adays get remunerative employment in intellectual work unless she can produce some proof of her attainments in the shape of a certificate of examination. And supposing a girl never does need to earn her own living, even then she secures for herself a locus standi, and betters her position vastly by having been successfully examined.

There is now no barrier hindering any woman because of her sex from ascertaining the exact value of her attainments, according to the same standard by which men are judged. In nearly all the examinations now open to women, men are candidates at the same time; and success in these examinations means that evidence of a certain amount of work and a certain quality of brain has been shown in the answers. If any girl fears an examination, being oppressed by the idea that men can naturally do intellectual work better than women, she should reflect that the ordinary type of man is not fond of intellectual effort, and that perseverance and patience will in a short time certainly place her above the commonplace members of both sexes. Moreover, successes attained by women show that this mark has been reached by many, and examiners have acknowledged over and over again that the mind of woman displays characteristics quite as deserving of respect as that of man.

735

All the examinations of the University of London are open to women, and degrees in arts, sciences, law, medicine, and music may be attained by them. The conditions of the examinations, and all the questions for one year, are contained in the Calendar of the university, published early every year; and the regulations and subjects for any particular examination can be obtained in the form of a small pamphlet from the Registrar of the University, Burlington Gardens, London. A degree cannot be obtained in a short time, but the examinations are open without any condition that the candidates shall have studied at a particular college, or at any college at all. It is necessary first to pass the matriculation examination, having produced a certificate of being at least sixteen years of age. A fair knowledge of Latin, and of two of the following three languages, Greek, French, and German; of English language and history, and modern geography; of arithmetic, elementary algebra, and geometry (the subjects contained in the first four books of Euclid); and of elementary natural philosophy and chemistry, is required. The examinations are held twice a year, in January and June, not only in London, but in some provincial centres, such as Manchester, Birmingham, and Bristol.

The examinations for the Arts degrees (B.A. and M.A.) require more advanced knowledge in mathematics, languages, and mental philosophy. The Science degrees (B.Sc. and D.Sc.) include almost the whole range of sciences which can be satisfactorily studied by all, but in the later examinations it is necessary to choose a few sciences for more thorough study.

To attain a medical degree it is requisite to study at a medical school, and for this purpose the only available place in England is the London School of Medicine for Women, established at Henrietta Street, Brunswick Square, W.C., the pupils of which receive instruction also at the Royal Free Hospital, in Gray's Inn Road. The Secretary of the School will always gladly furnish information about it to those who apply to her.

Nearly all British universities have established examinations for which women may be candidates. At Oxford there are examinations specially for women, the particulars of which may be learned of the Secretary. The Cambridge Higher Local examination is open to non-resident students of both sexes, and it is held at several populous centres besides Cambridge.

In both the Oxford and Cambridge schemes, single groups of subjects may be taken according to the choice or opportunities of the candidates. Thus at Cambridge there is a preliminary group including English language, history and literature, with arithmetic, which all must pass; and there are other groups of subjects, such as divinity, mathematics, languages, natural science, mental science, music, art, etc.

After the first group has been passed, it is possible to take up a single language at once, or a single subject of natural science, or more at pleasure.

Opportunity is given for showing higher attainments in all the subjects: and valuable, scholarships are awarded to those who are pecially distinguished, as also to younger students who do well in the Senior Local examinations, which are limited to those under eighteen years of age.

Yet higher advantages are within the reach of those who can manage to spend one or more years in Oxford or Cambridge. The benefits of residence at the older universities have long been acknowledged as regards men, and they are no less for women. At Oxford, St. Mary Hall and Somerville Hall receive women students desirous of being educated there; and at Cambridge, Girton and Newnham Colleges are established for a similar purpose.

The following extracts from the Memorandum of Association of Newnham College sufficiently exemplify the character of these institutions: "To establish and maintain at or near Cambridge houses or residences in which women students may reside and study; to provide for the instruction of women students, and for the delivery of lectures to such students, or to other women at or near Cambridge; and the doing of such other things as are incidental or conducive to advancing education and learning among women in Cambridge and elsewhere."

Residence in a university offers unique advantages: not only are the students receiving instruction from the ablest men

1870. and the labours and advocacy of some of the best men and women in the University and elsewhere have been devoted to maturing the system by which the present most excellent result has been secured, so that all opposition and prejudice have been overcome, and women students can now compete in the bonours examinations of the University, though not as yet for the money prizes and emoluments.

It is found that students derive greater advantage from spending their time at Oxford or Cambridge in advanced than in elementary work; and it is mach to be recommended that any who are hoping to go to Cambridge will pass their elementary examinations first, for they can thereby be exempted from the University Previous Examination or "Little Go." and commence at once to prepare for the advanced or honours examinations, which require a course varying from three to four years.

The examinations by which this exemption can be obtained are certain portions of the Senior Local and the Higher Local, and the Oxford and Cambridge joint exami nations; informa tion about these can always be obtained of the Secretaries By the Cambridge Triposes are meant those examinations by which the B.A. degree is obtained with honors.

of the age, but they are in constant association with other students who are kindred spirits, at any rate as regards their love of study. There is nothing to take the mind away from its object, but everything in intercourse, example and encouragement to lead a girl to succeed.

In addition to this, the social gain is important, for here girls from all ranks of educated society associate on equal terms, and the result of this is the refining of those who have not had early advantages in the usages of society.

Newnham College, of which alone we can find space for particulars, has two halls of residence closely adjacent, built to accommodate a principal, vice-principal, resident ladylecturers, and about seventy students. Each student has one room arranged to combine the purposes of bedroom and study, and in each hall there are a library, a dining-room, and other rooms for the use of the students in common. There are also lecture-rooms, a chemical laboratory, and a gymnasium. The lectures for women, out of which this College has developed, were first started in January

The titles of the principal Triposes

are the Mathematical, the Classical, the Law, the Natural Science, the Moral Science, the Historical, and the Theological. Plans of study are set forth in each of these departments of learning, involv ing at least three years' work for a sound and healthy brain already well trained by a previous education. Usually a portion of the subjects is indicated as elementary and neces sary, and the first part of the examination is separated from the rest; upon this it is deter mined whether candidates shall be permitted to enter the second part. Candidates are ar ranged in three classes of honours, and a place in the first class is intended to certify that the student has shown industry and good ability, and a real power of thought and grasp of the subjects. The names of female students who have passed each tripos examination are placed in a separate list according to the same standard as the men: and in cases where the first class is arranged i order of merit, the place of each female student is given according as it would have been placed in the list of the men.

However, the formal degree is not yet granted to women at Oxford and Cambridge, but no doubt for this there is a good time coming.

ZOOLOGY.

XXXI.

protecting the

ZEBRA.

bone. In all, the large brain or cerebrum does not extend backwards far over the small brain or cerebellum.

THE ODD-TOED UNGULATES.

The most satisfactory division of this great group is that into odd- and even-toed, reckoning by the hind foot. The horse, Odd and evenas is well known, has but a toed. single complete digit, while the ox has two. In the odd-toed section, the middle or third digit is largest, and when others are present, they are the second and fourth, the first being always lacking. With this feature we find associated an uncomplicated stomach, and a remarkable enlargement of the first part of the large intestine, called the blind gut. No horns growing upon a bony core occur in this section.

The Horse Family.

This family is the only group of mammals in which the effective digits are reduced to a VOL. II.

737

single one for each limb. Rudiments of two others remain, and in extinct horses these rudiments are found to be gradually larger as we go backwards in time, until a completely three-toed animal is reached. In the hoof of a horse merely the last bone of the middle finger or toe is enclosed, and the rest of the foot is almost upright. What is often called the "knee" of a horse really corresponds to our wrist, while the projection in the middle of the hind leg, called the "hock," is the true heel. The so-called "cannon-bone".

answers to the middle long bone Peculiarities of limbs of our palm and sole, much lengthened and thickened. On either side of the cannon-bone is a small "splint bone representing the long bones of the second and fourth digits. The enveloping of the last bone of the digit in a thick horny hoof enables it to bear the weight of the animal well, and to undergo the sudden concussion which occurs in

HARTE-BEESTE.

running; while the positions of the arm and thigh-bones, the first passing obliquely forIwards, and the latter obliquely backwards, and scarcely distinguishable from outside, give the most spring-like arrangement for rapid and safe action.

The skull is much elongated, and contains a posterior. part, in which the little brain lies, not covered by the cerebrum. The snout is long,

Skull.

Teeth.

and the eyes, placed rather far back, are entirely engirt by bone. The back part of the lower jaw is deep, and gives rise to powerful grinding muscles. The teeth constitute a striking and important feature; the large grinders have patterns, produced by the alternation of enamel, dentine, and cement or tooth-bone, which are gradually worn away by use, leaving an uneven surface always exposed. The total number of permanent teeth is forty, including six grinders on each side. Each of the incisor teeth has a deep inner fold of enamel, the latter forming an encircling ridge round the pit, which is filled up with compressed food. The

ridge gradually wears away, form- The "mark." ing a "mark of differing shape at different ages up to about eight years old, when the mark has entirely disappeared on all the teeth. All existing horses can be included in one species-even the wild horses of Tartary, South America, and Australia. It is not considered

47