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pointer in the vertical post exactly level with some characteristic point in the load end of the pulley block. Then move the spring-balance end upwards through a distance of say 10 inches and set the lower pointer level with the same characteristic point. Measure, with a boxwood or steel scale, the distance of the underside of the 7 lbs. weight from the floor. This is the distance moved by the driving end, while the load end has moved through the distance between the two pointers P and N.
Repeat the measurements with other movements, and results something like the following will be obtained :
2.6 3:1 33 3:3 34 3:5 3:5 3:5
7 14 21 28 35 42 49 56 63 70 77 84 91 98 105 II2
8.5 10'3 12'o 13-9 16:1 1794 19'3 212 23.0 25.5 27'0 29'0 310
9 195 2:8 3o7 4? 57 6.5 8:0 8.9 95 10-5 ITo7 12'5 13'5 147
0:54 0.62 0.66 0.66 0.68 0970 070 071 0*72 0.72 072 072 0°72 0972 0°72 0*72
Now plot these quantities on squared paper as in Fig. 7, and draw a straight line through the average position of the points.
36 3.6 36 36 36 36 36 36
Distance moved by load!
end in inches.
The fourth and fifth columns have been calculated with a 25
slide rule, and the third significant figure omitted.
To obtain the general relations between the load and the
other quantities we must plot these quantities on squared paper, 10 20 30
using a load base. This has been done in Fig. 8.
The line GLC is the driving force line (listing), and DH the Distance moved by driving end in inches.
same when lowering ; that is, the ordinates from the base to
these lines represent the several values of the driving force. Should any of these lie far from the line, we may remember that Similarly, the curve BF gives the mechanical efficiency at the theoretical considerations show that the line passes through the different loads, and as the mechanical advantage the me origin. The slope of the line gives the ratio :
chanical efficiency multiplied by a constant (VR), the same Movement of load end Movement of driving end,
of which by definition
107 velocity ratio. From the measurement of the slope we 30
0-6 obtain as nearly as possible 5 for the velocity ratio. This is the number which we ought to obtain ; as the number of ropes supporting the load end is five. 20
0.4 Remove the 7 lbs. from the spring balance. Pull steadily on the spring
03 balance hook with both hands, 10
02 making it move at a uniformn rate; at the same time read the indication of
0.1 the pointer. It was 45 in the experiment being described. Now determine the driving force which
Load in lbs. will permit the machine to run back
Fig. 8. wards. This is done by allowing the spring balance to move in the reverse direction at curve also represents the mechanical advantage to another scale the same rate as in the forward direction and ob- in which the divisions are smaller in size and equal to serving the indication. It was about o.9 lb.
length of efficiency scale divisions Now change the load to, say, 21 lbs.and repeat the
velocity ratio. observations, after which the load is further changed As the driving force lines are straight, we can write down until the complete range has been used. The ob- their equations. The general equation to a straight line is
Driving force in lbs.
the slope x the
friction is represented by M N, and therefore N C represents a vertical ordinate=a constant + corresponding horizontal the friction. From this we see that the vertical intercept between
the line G C, and that through N and the origin, represents But in this case vertical ordinates represent driving force, and the friction. Now friction always opposes motion, and con. horizontal ordinates the load ; hence we may write the above sequently when the machine is running backwards, friction is equation
still opposing motion, that is, it is trying to prevent the machine Driving force = a constant + slope + load.
from running backwards, and is therefore assisting the driving
force. Consequently, the actual driving force applied by the СЕ
19 The slope of the line GC is
27 and the con- hand while the machine is running backwards equals the driving EL 70
force without friction minus the friction. The difference be. stant is the height (1) at which the line GC cuts the vertical tween this expression and the last equation is twice the friction. axis at G; hence the above equation becomes :
Hence the vertical intercept between the lines G C and D II Driving Force 1+ 27 load.
represents twice the friction at the particular load in question.
For example, at the load D M = 112 lbs., the intercept HC This is the general relation between the load represents twice the friction. Hence bisect any intercept and and driving force for any range of loads. Further, we get the friction at that load. The points of bisection will lie the mechanical advantage equals the load divided on the line through N and the origin. by the corresponding driving force. Substituting for the driving force from the above equation we
This shows how the effect of friction may be got have:
rid of, should such be required. The line through
N and the origin may be called the ideal driving.
load Mechanical Advantage driving force
force line. load
It is often stated in text books that a machine I + 27 load.
will not run backwards of its own accord if its Also the
efficiency be less than 50 per cent.; but the fact is Mech. Advantage Mechanical Efficiency
seldom demonstrated so that the junior student VR.
can appreciate it. load
Returning to Fig. 8, we have seen that the line (1 + 27 load) velocity ratio.
through N and the origin (the ideal driving-force This last equation is the equation to the curve BF in Fig. 8, line) bisects the vertical intercepts between D H the dotted portion of which is obtained by substituting different and G C. Let us pass to a machine which is less values for the load between zero and 7lbs. This should also be efficient than the one just considered, but one in done where the points are very irregular in the curve BF, such which the same driving force and load relationship as the fourth, fifth and seventh points.
holds. This will necessitate the velocity ratio We may obtain the portion of the driving force
being greater than (5), which is that of the machine required to overcome friction in two ways. From just considered. The friction being greater than theoretical considerations we know that, if there before, the line through N will be lower than in were no friction, the driving force would equal Fig. 8, and consequently the line D H will have a load
much less slope, the point H being considerably
lower. velocity ratio.
If we carry the argument still further the line If we subtract this from the actual driving force D H will eventually fall entirely below the base (with friction), the difference must be that portion line, indicating that a negative driving force must of the actual driving-force required to overcome be applied to compel the machine to run backwards; friction. This we generally call simply the friction
as we actually find in the screw jack and the for brevity. We may then write
load friction actual driving-force
Now consider the case in which the point H has fallen to M. VR.
The machine will run backwards with a load D M with no = 1 + 27 load 2 load
driving force (positive or negative). The corresponding point N = + '07 load.
must be half-way up M С, or in other words, the friction NC is The first term is due to the weight of the parts of half the driving force MC, and consequently that portion of the machine alone, while the second term is due to the driving force which is doing useful work in listing the load is the load alone.
MC The second method of determining the friction
That is, of the whole driving force M С, half of of a machine is also interesting. From the above
it is spent in doing useful work and half in overcoming friction ; we have learnt that
therefore the efficiency of the machine is t, or 50 per cent. the actual that reqd, to that reqd. to
NM driving- list load without +
If now the point H drops below M, we shall have to
apply a negative driving force to run the machine backwards ; The first term on the right we have already found to be that is, it will not run back of its own accord. At the same 0-2 load. Substitute the different values of the load in this time, if H drops below M, N will drop below the middle point term and plot them in Fig. 8. We then get the line passing of M C, and the useful driving force, M N, will be less than through N, and the origin. Then with the load of 112lbs. half the total M С, or the efficiency will be less than 50 per represented by DM, the actual driving force is represented by cent. ; hence the machine will not run back of its own accord if MC, and the driving force required to list the load WITHOUT its efficiency is less than o's.
suitably educated members of the race, it will be PORTENTS AUGURAL.'
interesting to note what, in view of the trend of
things, “suitably educated ” means. The trained HERE are several reasons why the writings capables of the year 2,000 will be
of Mr. H. G. Wells find many readers among schoolmasters.
He has passed
a great inchoate mass of more or less capable people engaged through the same mill as themselves and knows more or less consciously in applying the growing body of scie the intensity of the pressure between the upper
tific knowledge to the general needs, a great mass that will and nether stones. As similar circumstances tend
inevitably tend to organise itself in a system of interdependent to the development of like characteristics and
educated classes with a common consciousness and aim .... interests, they find themselves attracted by what What will fit men to take their places among Mr. Wells says, whether it be a direct expression the elect at the beginning of the twenty-first of opinion in a didactic essay or the utterance of century ? Mr. Wells never leaves his reader in one of his characters. His incisive style, inde- any doubt. It is, in a word, thorough, sane pendent thought, and fertile imagination unite to education : command their appreciation and create a desire to emulate him.
The necessary condition to the effective development of the For these reasons, and because the development
New Republic is a universally accessible, spacious, and varied and improvement of the human race is largely a
educational system working in an atmosphere of efficient critiquestion of educational procedure, we do not
cism and general intellectual activity. Schools alone are of no hesitate to direct the attention of our readers to the
avail, universities are merely dens of the highest cramming,
unless the schoolmasters and schoolmistresses and lecturers are most recent book of this author. “Anticipations'
in touch with and under the light of an abundant, contemis a serious attempt at prophecy which places Mr.
porary, and fully adult intellectuality. Wells among our philosophers and assures him a high reputation as a perspicacious student of
There is, however, urgent need of an absolutely new type of human nature and affairs.
school-a school that shall be at least so skilfully conducted In Hebrew history a man is described as a
as to supply the necessary training in mathematics, dialectics, prophet for one of two reasons; either because he
languages and drawing, and the necessary knowledge of
science foretold future events, or else, as when Ezekiel prophesied to the dry bones, by reason of his
The war of the coming time will really be won in schools exhortations. Mr. Wells must be placed among
and colleges and universities, wherever men write and read and the prophets on both these accounts, for he not
talk together. The nation that produces in the near future the only diagnoses the future, but makes it clear, even
largest proportional development of educated and intelligent to the wayfaring man, how possible dangers may
engineers and agriculturists, of doctors, of schoolmasters, probe averted. With an intimate knowledge of
sessional soldiers, and intellectually active people of all sorts
. , will certainly be the ascendant or dominant nation modern science and the teachings of Darwin and
before the year 2000. his school, supplemented by a good working acquaintance with the histories of the great peoples
The teacher will teach, and confine his moral training, of the earth, Mr. Wells applies his scientific beyond enforcing truth and discipline, to the exhibition of a imagination, having throughout a careful regard capable person doing his duty as well as it can be done. He to modern tendencies, to the task of unfolding the
will know that his utmost province is only a part of the lines along which mankind will evolve and what
educational process, and that equally important educational will probably be the distribution, divisions, and
influences are the home and the world of thought about the distinguishing characteristics of the people living pupil and himself. in the year 2,000.
Describing the education of the future as he It is perhaps a little unfortunate that Mr. Wells does, it was inevitable that Mr. Wells should give has already written “When the Sleeper Wakes" his estimate of our modern school-system. His and “ Tales of Space and Time," not only because verdict is far from flattering. He never, we think, many readers will at first imagine “Anticipations" | merely vituperates; his censures always breathe
; is another scientific romance, but more especially of an earnest desire to bring about an improved since he has found it necessary to modify some of condition of things. Not only when treating of his previous beliefs as to the dominant section of modern education, but throughout, the book is humanity in the years to come. A prophet, to strong food for men, and to such adults it is carry conviction with the mass, that is—must be certain to prove a tonic, even though it should be dogmatic and insistent. Yet this very failure to an unpalatable one. impress the crowd will be itself a great attraction We have, perforce, confined our attention to for thinking persons.
Here," such a reader will one aspect only of this message to struggling say, “is an earnest effort to find the truth.”
humanity, yet there can be no doubt that all the It would be out of place for us to attempt to subjects of the author's prophesyings will interest sketch, even roughly, the varied contents of teachers, while the charm of his English, the
, "Anticipations.” But since the effective rulers throbbing, living appeals to the wise reader's of the New Republic are, it is argued, to be the reason, and the triumphant march of his descrip
tive passages, will much more than repay the 1" Anticipations of the Reaction of Mechanical and Scientific Progress expenditure of time demanded by the perusal of upra Human Life and Thought." By H. G. Wells. (Chapman & Hall.) the book.
No. 37, Vol. 4.)
of the upper division of intermediate schools into a COMMERCIAL EDUCATION.
commercial and an industrial section. (d) The crea
tion of a modern department without bifurcation in N Mr. Whitfield's book' we have: (1) A survey first-grade schools. (c) The establishment of insti
tutes of commerce with a three-years' course for different countries. (2) Proposals for a com- boys of 16 years of age and upwards. Why plete system of commercial education in England. should not the first-grade school provide this (3) Suggestions on methods of teaching with a training ?) The establishment of post-graduate miscellaneous amount of information bearing on (sic) courses, such as the School of Economics commerce.
provides. (1) The account given of “Commercial Edu- (3) The third portion of the book is made up of cation" in the German Empire is quite misleading. diffuse talk and a patchwork of quotations. But it Compulsory attendance at continuation schools in contains much that is suggestive to teachers. Prussia is a matter of local option, and is the The most valuable feature of the book is the exception, not the rule. Pupils of intermediate ample bibliography furnished on the various topics modern schools, when destined for business, do not, discussed. except in isolated cases, pass to higher mercantile By “ commercial education,” say Messrs. schools. The fact is that the modern schools Hooper and Graham in the second book' under themselves keep in view the requirements of com- notice, "we mean a practical education suited to mercial life. Higher mercantile schools so-called the needs of the present day, and calculated to fit are to be found in only three towns of Prussia, viz., young people intended for business careers for the Cologne (2nd grade), Frankfort o/M. (1st grade), work they will have to perform, and to better Aix-la-Chapelle (1st grade). Saxony, on the other equip for the work those already in business.” hand, does provide a very fair number of “com- This definition begs the whole question of the mercial schools” of a more pronounced type than curriculum ; it assumes at once that it is the practhe Realschule, and continuation schools with tical course of study, such as the authors lay down compulsory attendance are to be found throughout without any appeal whatever to psychology, that the kingdom. Much is made of the regulations of is best calculated to fit people for business. It is the Bavarian Government relating to“commercial" this very contention which is rebutted by many teachers; the truth is that their application is so schoolmasters who cling to school traditions. In limited that they afford no indication whatever of the interests of commercial education we wish that the qualifications of masters in German commercial the authors had gone more deeply into the matter, schools. More accurate treatment is accorded to and had presented us with something more conFrance. The patent omission is the explanation of vincing than their insistence on the educational the attractiveness of the twelve “superior” schools aspect of a commercial curriculum. of commerce. It is well known that their roll-call Five essentials are given for a course of higher is a vastly exaggerated measure of the genuine commercial education, following the ordinary demand for higher commercial instruction, that in secondary school course :-Modern Languages, fact the "superior” edifice would shrink to perhaps Commercial Practice, Study of Materials, .Prina tenth of its present dimensions were it to lose ciples of Commerce, Commercial Law. The the exceptional privilege relatively to military methods of study of the various subjects falling service. The author makes no mention of the under these groups are discussed. “Ecoles Pratiques de Commerce" (under the Under “Modern Languages" we are urged to Ministry of the Industry and Commerce) which abandon our “trifling" attitude, to do our work are to be found in a large number of French towns. thoroughly and to pursue our methods educaMuch useful information is given us in connection tionally, bearing in mind that the tongue must with the United States and Japan. The part be trained equally with the ear and the eye. To dealing with the United Kingdom is comprehensive
this excellent advice a useful addition would have and accurate.
been the sketch of a syllabus for commercial (2) With regard to the future organisation of schools, showing how far commercial requireour commercial education, the following proposals ments necessitate a supplement to the ordinary are made :-(a) The creation of commercial sides literary pabulum. It is right that our attention at higher elementary schools. We imagine that should be drawn to the demands made by Eastern the boys from 12 to 14 years of age will have to be markets on a knowledge of Oriental languages. somewhat precocious, if they are to make much of We are shown what the Universities of Berlin, the ambitious curriculum that embraces modern Paris, and Vienna have done to meet the want; languages, book-keeping, commercial geography, but the authors seem evidently to be ignorant of and object lessons on trade products, simplified
the existence of the School of Oriental Languages economics, elementary mathematics, science, draw- attached to the Imperial Institute in London. ing, shorthand, "business training."
The “ Commercial Practice" course, as described further formation of evening continuation schools by Messrs. Hooper and Graham, co-ordinates the for boys employed in offices. (c) The bisurcation study of the machinery of business, book-keeping,
1 “Commercial Education in Theory and Practice." By E. E. Whitfield, M.A. (Metbuen & Co.)
1 " Commercial Education at Home and Abroad." By Frederick Hooper and James Graham. (Macmillan & Co.)
and arithmetic. It affords an excellent training for the clerical work that the commercial assistant
TWO AMERICAN MANUALS OF is called upon to perform. We are inclined to
GENERAL HISTORY.' think, however, that for higher commercial requirements the treatment of the whole subject should
HE American School and College Text-Book be more scientific, or that, at any rate, it should
Agency have sent us two of the four manuals be taken simultaneously with or subsequent to
of General History which appear in their " The Principles of Commerce
and “Com catalogue. The subject is not familiar to us over mercial Law."
here; it does not appear in the syllabus of any of More than half of the book before us deals
our public school-examinations; and apparently
few teachers think it worth while on their own with the actual provision of commercial education in different parts of the world. Germany, of
initiative to introduce the subject, even though course, leads the way. In spite, however, of the they believe as heartily in its utility as does Mr. prominence given to this country, it will appear,
W. M. Childs (see School World, April, 1901). both from the map and the list of schools, that,
But it seems to be taken up in American schools so after all, not very much has been done in the way
extensively that publishers thought it worth while of specialised commercial instruction over and producing twenty or thirty different books to meet above that given in elementary continuation
the demand. Some of these are compilations put classes. The diagram showing the organisation together with more or less care by persons who of commercial education in Germany has no rela
have not had a scientific training in history; others tion to actuality. The whole section on “Com
are by university professors, some of whom have mercial Education Abroad " seems to have been
a European reputation. Both the varieties are derived from prospectuses of schools, and is for exemplified in the two books before us.
Anderson's “New Manual of General History that reason misleading in the extreme. The thing becomes ridiculous when, in the case of Leipzig,
bears on its title page the date of 1899, but the pre
face is dated 1882, and there are many signs in the the prospectus of the “Handelslehranstalt (Secondary School of Commerce) slips into the
book lists, &c., that the book has either not been reprogramme of the “ Handelshochschule” (Con cently revised or has been revised very badly. The mercial University). Boys of second-grade secon
book is not attractive in outward show, and as for dary-school age are made to have a curriculum
the text, here is a fair sample from a chapter on the embracing such subjects as finance, international
Progress of Civilisation in Modern Europe :law, statistics, German colonial policy!
Modern history commences at the epoch at which the dawn of When we come to “ Commercial Education intelligence broke upon Europe. In the latter part of the at home, we find that the United Kingdom and fifteenth century the civilisation of the Greek Empire had the West Riding of Yorkshire are co-extensive. disappeared before the conquering arms of the rude and We are indeed furnished with some extremely ferocious Ottomans; and the western nations, emerging from the interesting and useful information of what has night of mediaeval ignorance, began to glow with the first beams been achieved in Messrs. Hooper and Graham's
of that intellectual and social illumination to which they have county; but “ Particulars of what has hitherto attained. been done in the United Kingdom" should Teachers who still
Collier may agree embrace more than the Yorkshire experiment. with the author in regarding this as written "in The work done by London Polytechnics, School a pleasing and instructive style"; but for our Boards, the School of Economics, and some of the own part we think the “outline reviews, topical large day-schools is surely deserving of mention synopses, and chronological tables" with which the and even of description.
book is copiously supplied are more deserving of approbation--and indeed of imitation in historical
manuals generally. On the whole, the book strikes d Class Book of English History. By Arthur Hassall.
us as not worth the trouble of transportation; and xix. +603 pp. (Rivingtons.) 35. 6d.—This is a handy and
we hope that teachers will discourage this particular useful outline of the facts of English history, well supplied with
"immigrant alien" by ignoring its existence. maps, plans, tables, “notes and illustrations” (not pictorial),
The other book stands on a wholly different and a full index, and well deserving to be put into the hands of
footing. The author is Professor of Economics in the candidates for the various examinations mentioned on the
the University of New York, and is—if we may title-page. But there is very little depth in it. The teacher will require to supply, for the most part, explanations of the judge from his portrait in the publisher's excellent
catalogue - young and alert.
not movements here narrated, especially of the drift in matters constitutional. On the whole it fulfils the author's promise
personalities. Mr. Colby's youthfulness accounts
both for the briskness of his style and for a certain of being written in the light of the most recent research ; but we have noted that he still attributes many grammar schools to
amount of inexperience in his terminology; while Edward VI., that he retains “Morton's fork” in the text,
as for his position it may safely be said that, though “discrediting ” it in a footnote, that he thinks the word
1 "New Manual of General History for the use of Colleges, High "Cabal” was made out of the initials of its members, and we Schools, Academies, &c." By John J. Anderson, Ph.D. 683 pp. (New think his account of the Statute De Tallagio non Concedendo York : Maynard Merrill & Co.) 8s.
“Outlines of General History." By Frank Moore Colby. 564 +Ixii. pp. does not conform to "Stubbs.” But the greatest complaint we (Bibliography and Index.) (New York: American Book Co.) 73. od. have to make is the author's apparent ignorance of Puritan and
Each book has about 200 illustrations and maps, many coloured ; and
both are on sale, at the prices named, at the American School and College Separatist, Presbyterian and Congregationalist history.
Text-book Agency, 9, Arundel Street, Strand, W.C.