490 



NA TURE 



[September 29, 1923 



Suggestions and criticisms are invited. Mozart's 

 " Magic Flute " will supply some items of music, 

 especially on March i. Admission will be free, 

 without ticket. 



Secondary education in the United States in 1921 

 and 1922 is reviewed in Bulletin, 1923, No. 12, of 

 the Bureau of Education, Washington. The out- 

 standing achievement within the past few years has 

 been an extension downwards of the secondary school 

 system in many parts of the United States, especially 

 in cities. Typically, the extension hcis taken the form 

 of substituting for the normal sequence of 4 years of 

 high school work following 8 years (a^es 6 to 14) of 

 elementary schooling, a system sometimes described 

 as the 6-3-3, meaning 6 years (ages 6 to 12) of 

 elementary schooling followed by 6 years of secondary 

 school work divided into two administrative units of 

 3 years each, namely, the junior high school and the 

 senior high school units. Essentially the change 

 implies that the passage from the elementary to the 

 secondary type of curriculum should synchronise with 

 the commencement of the physical changes of adoles- 

 cence. It is generally agreed in America that at this 

 stage the pupil needs in his studies change, variety, 

 and human interest rather than completeness and 

 logical arrangement, and that consequently in place of 

 the traditional seventh and eighth grade courses there 

 should be a general survey of the chief departments of 

 knowledge : " English literature, general social science, 

 general mathematics, general science, foreign lan- 

 guages for those who desire them, music, art, physical 

 education, and the practical arts." This holds good 

 both for those who are to leave school at 15 and 

 for those who are to pass on to the senior high 

 school. 



A STATISTICAL survey of education in the United 

 States is given in Bulletin No. 16 of 1923 of the 

 Federal Bureau. It shows the following total enrol- 

 ments in 1919-20 (in thousands) : kindergarten 511, 

 elementary 20,383, secondary 2430, university, college, 

 and professional school 462, teachers' college and 

 normal school 163 ; grand total 23,950, being 22-7 

 per cent, of the total population. Included in the 

 above are the following enrolments in private, that 

 is non-state, institutions : kindergarten 30, elementary 

 i486, secondary 229, university etc. 281, teacher- 

 training 14. The estimated cost of all this education, 

 except private elementary and private secondary, is 

 1 30 1 million dollars, or, in dollars per head : element- 

 s^T 39, secondary 127, university, college, and pro- 

 fessional 460, teachers' college 131, other normal 

 schools 189. The figures are exclusive of city evening, 

 private commercial, nurse-training, and Indiem and 

 Alaskan schools. Enrolments in these amounted to 

 587, 336, 55, and 32 thousands respectively. Gifts 

 and bequests to education in 1920 reached the un- 

 precedented total of 67 million dollars, the highest 

 previous record being 37 million in 191 6. The extent 

 to which women teachers have taken the place of men 

 during the past 40 years in elementary and secondary 

 schools is strikingly shown in a table in another 

 Bulletin, No. 29 of 1922, giving the percentage of 

 men teachers in 1880 and at the end of each subsequent 

 quinquennium up to 1920 : 43, 37, 35, 33, 30, 24, 21, 

 20, 14. The average annual salaries in dollars of all 

 teachers, men and women, in the same years are given 

 as 195, 224, 252, 286, 325, 386, 485, 543, 871, but the 

 last figure includes supervisors and non-teaching 

 principals. During the past 50 years the ratio of 

 pupils in secondary schools, compared with the total 

 enrolment in elementary and secondary schools 

 combined, increased from 1-2 to 10-2 per cent. 



NO. 2813, VOL. I 12] 



Societies and Academies. 



TENDON. 



Institute of Metals (.Manchester Meeting;), September 

 10. — Sir Henry Fowler: The use of non-ferrous 

 metaLs in engineering (Autumn Lecture). Of the 

 non-ferrous metJils u.sed by engineers, the one which 

 has been in longest use Ls copi>er, and it Is at present 

 the one most closelv a,s.sociatea with engineering work. 

 The uses to which its comparatively simple alloys 

 with tin and zinc can be put arc endless. The next 

 in importance is tin, wliich, alloyed with copper, lead, 

 and antimony, gives us those white metals which 

 are used to make bearings in machines. Aluminium 

 is still most generally used in connexion with aero- 

 nautics. 



September 11. — E. A. Bolton: The cause of red 

 stains on sheet brass. The stains occur through re- 

 actions of copp>er oxides in the scale formed during 

 annealing and in the pickling medium. Cupric oxide, 

 contrary to the usual opinion, is as harmful as 

 cuprous oxide. The presence of these oxides may be 

 due to careless washing after pickling, resulting in 

 the presence of acid and salts during annealing, the 

 presence of iron in the brass or upon its surface, the 

 use of impure rolling oils, etc. The main cause of 

 the oxidation of the copper is the use of old-fashioned 

 annealing furnaces in which the flames impinge 

 directly upon the brass. Possible remedies for the 

 red-stain trouble are suggested. — H. W. Brownsdon : 

 Brinel hardness numbers. Brinel numbers for non- 

 ferrous metals should be expressed in figures that 

 are comparable. This could be done if balls and loads 

 are used for which the ratio L/D* (the load in kilograms 

 divided by the square of the ball diameter in millimetres) 

 is constant. Some one ratio for L/D* should always 

 be used for one class of alloys ; for the copper aUoys 

 with Brinell hardness numbers from about 40 to 200, 

 the choice should rest between the ratio 5 as stan- 

 dardised in the United States or the ratio 10 which 

 is favoured in some quarters in Great Britain. — A. H. 

 Mundey and John Cartland : Stereotyping. Stereo- 

 typing is generally regarded by printers as almost a 

 trade secret. The process was invented by a practical 

 metallurgist, William Ged, an Edinburgh goldsmith, 

 in 1750. Stereotyping wjis traced from the plaster- 

 of-Paris process to the use of papier-mache fiong, and 

 from the simple stereo plates for flat-bed machines to 

 the elaborate requirements of the modem newspaper. 

 A high degree of accuracy is demanded in the mech- 

 anical and metallurgical details in order to produce 

 the good results which are a commonplace to every- 

 one. — J. D. Hannah and E. L. Rhead : Crystallisa- 

 tion effect on galvanised iron sheets. Manufacturers 

 of galvanised iron and steel goods always seek to 

 produce a zinc-covered surface having large char- 

 acteristic spangles. Small spangles or lack of 

 spangles is disUked. The metal — iron or steel — has 

 practically no influence on the result if the tempera- 

 tures are satisfactorily maintained. Pure zinc does 

 not yield large spangles, and too high a temperature 

 interferes by producing large quantities of a zinc-iron 

 compound which crystallises in needles on the metal. 

 The presence of tin or aluminium does not produce 

 the desired result, but lead is effective. The separa- 

 tion of the impure zinc into conjugate solutions, lead- 

 rich and zinc-rich, at the dipping temperature, and 

 the method of subsequent cry-stallisation, may be 

 the causes of these effects. — R. C. Reader : Effects 

 of rate of cooling on the density and composition of 

 metals and alloys. The densities of pure metals, and 

 of alloys which solidify at a constant temperature, 

 are not affected by the rate at which they soUdify. 



