MATHEMATICS TEACHERS ASSOCIATION OF RHODE ISLAND.

President, Alden E. Hodgkins, Technical High School, Providence; Vice-President, Henry K. Sears, Hope St. High School, Providence; Secretary-Treasurer, Professor Clinton H. Currier, Brown University, Providence.-118.

MISSOURI SOCIETY OF TEACHERS OF MATHEMATICS AND SCIENCE.

President, O. M. Stewart, Columbia; Secretary, B. F. Finkel, Springfield; Treasurer, A. J. Schwartz, St. Louis. Mathematics Division: Vice-President, Wm. A. Luby, Kansas City; Secretary, Miss Eula A. Weeks, St. Louis. Science Division: Vice-President, H. L. Roberts, Cape Girardeau; Secretary, Miss Loula VanNeman, Kansas City.-118. NATIONAL EDUCATION ASSOCIATION.

President, Mary C. C. Bradford, Denver, Colo.; Secretary, J. W. Crabtree, Washington, D. C.; Treasurer, A. J. Mathews, Tempe, Arizona. NEW ENGLAND ASSOCIATION OF CHEMISTRY TEACHERS.

President, George A. Cowen, West Roxbury High School, Jamaica Plain, Mass.; Vice-President, William W. Obear, High School, Somerville, Mass.; Curator, Lyman C. Newell, Boston University, Boston, Mass.; Secretary, S. Walter Hoyt, Mechanic Arts High School, Boston, Mass.; Treasurer, Alfred M. Butler, High School of Practical Arts, Boston, Mass.-118.

NEW JERSEY SCIENCE TEACHERS' ASSOCIATION.

President, Earl Eastman, Atlantic City High School, Atlantic City; Vice-President, Merton C. Leonard, Dickinson High School, Jersey City; Secretary-Treasurer, Raymond S. Blodgett, Caldwell High School, Caldwell; members of Executive Committee: Dr. Melville T. Cook, Rutgers College, New Brunswick; Miss Agnes V. Luther, State Normal School, Newark; H. Morgan Campbell, Bayonne; Section Chairmen: AgricultureBiology, Dr. C. H. Robison, State Normal School, Montclair; Chemistry, Charles E. Dull, South Side High School, Newark; Elementary Science, Miss Caroline G. Howe, South Side High School, Newark; Physics, E. R. Vactor, West Hoboken High School, West Hoboken.-118. NEW YORK STATE SCIENCE TEACHERS' ASSOCIATION.

President, H. A. Carpenter, 1736 Church St., Washington, D. C.; Vice-President, M. C. Collister, 2303 Sunset Ave., Útica, N. Y.; SecretaryTreasurer, E. E. Ford, West High School, Rochester, N. Y.; Council members: Prof. R. C. Gibbs, Cornell University, Ithaca, N. Y.; C. Caulkins, Elmira, N. Y.; Edward L. Long, High School, Saugerties, N. Y.; Chairman of the Physics and Chemistry Section, R. A. Crumb, High School, Binghamton, N. Y.; Chairman of the Biology Section, Mrs. Roberta Parke, Masten Park High School, Buffalo, N. Y.; Chairman of the Earth Science Section, Melvin E. Coon, West High School, Rochester, N. Y. -1117.

OHIO ASSOCIATION OF TEACHERS OF MATHEMATICS AND SCIENCE.

President, J. D. Boldt, Stivers High School, Dayton; Vice-President, Prof. William Holt, State Normal, Bowling Green, Ohio; SecretaryTreasurer, H. M. Beatty, Columbus, Ohio.-118.

THE PHYSICS CLUB OF NEW YORK.

President, Roland H. Williams, Horace Mann School for Boys, New York; Vice-President, Fred F. Good, Teachers' College, New York; Secretary, Arthur L. Yoder, Richmond Hill High School, New York; Treasurer, John O. Scudder, Morris High School, New York.-118. SOUTHERN CALIFORNIA SCIENCE AND MATHEMATICS ASSOCIATION. President, Agnes Wolcott, High School, Long Beach; Vice-President E. E. Chandler, Occidental College; Secretary-Treasurer, Harriet S. King, High School, Pasadena.-118.

WASHINGTON ACADEMY OF SCIENCES.

President, Lyman J. Briggs, of the Bureau of Plant Industry; Corresponding Secretary, Robert B. Sosman, of the Geophysical Laboratory; Recording Secretary, W. R. Maxon, of the National Museum; Treasurer, William Bowie, of the Coast and Geodetic Survey.

Hawkes, Luby, and Touton Algebras

have come to have significant meaning in

school mathematics

They fix one algebraic idea in the pupil's mind before a new one is introduced. They make the subject really interesting and help, through their portraits and historical notes, to bring out the human side of the subject.

They give pupils a firm grasp of the processes of algebra.

They introduce the equation early and frequently.

They develop factoring gradually.

They furnish the pupil systematically with methods of checking results. They grade exercises and problems carefully, and correlate algebra with arithmetic, geometry, and physics.

Caldwell and Eikenberry's General Science (Revised)

Recent important scientific discoveries are responsible for this revised edition, which follows the same excellent style and form that made the first edition so widely popular. In addition, there has been a thorough rewriting of the text; new chapters have been added on electricity; a set of important application problems for each chapter; and much new material on household industries and art. $1.28.

GINN AND COMPANY

Boston New York Chicago London Atlanta Dallas Columbus San Francisco

EDUCATIONAL PRESS ASSOCIATION OF AMERICA President, Henry G. Williams, Columbus Ohio; Vice-President, H. R. Pettingill, Lansing, Michigan; Secretary, G. L. Towne, Lincoln, Nebraska; Treasurer, S. Y. Gillan, Milwaukee, Wisconsin; Executive Committee: O. T. Corson, Columbus, Ohio; H. T. Musselman, Dallas, Texas.

Members.

American Education, Albany, N. Y., C. W. Blessing, Editor; American Journal of Education, Milwaukee, Wis., S. Y. Gillan, Editor; American School, Milwaukee, Wis., C. G. Pearse, Editor; American School Board Journal, Milwaukee, Wis., Frank Bruce, Editor; Atlantic Journal of Education, Baltimore, Md., H. E. Buckholz, Editor; Colorado School Journal, Denver, Colo., D. R. Hatch, Editor; Educator-Journal, Indianapolis, Indiana, L. N. Hines, Editor; Florida School Exponent, Tallahassee, Fla.; Journal of Education, Boston, Mass., Dr. A. E. Winship, Editor; Kansas Teacher, Topeka, Kansas, F. L. Pinnet, Editor; Kindergarten-Primary Magazine, Manistee, Mich.; Manual Training Magazine, Peoria, Ill., Chas. A. Bennett, Editor; Moderator-Topics, Lansing, Michigan, H. R. Pettingill, Editor; Missouri School Journal, Jefferson City, Mo., T. J. Walker, Editor; Midlands Schools, Des Moines, Iowa, C. R. Scroggie, Editor; Nebraska Teacher, Lincoln, Nebraska, Geo. L. Towne, Editor; New Mexico Journal of Education, Santa Fe, Rupert F. Asplund, Editor; Ohio Educational Monthly, Columbus, Ohio, O. T. Corson, Editor; Ohio Teacher, Columbus, Ohio, Dr. Henry G. Williams, Editor; Oklahoma School Herald, Oklahoma City, Mrs. Sibyl Dunn Warden, Editor; Pennsylvania School Journal, Lancaster, Dr. N. C. Shaeffer, Editor; Popular Educator, Boston, Mass.; Primary Education, Boston, Mass.; School and Home Education, Bloomington, Ill., Geo. Brown, Editor; School Bulletin, Syracuse, N. Y., S. Y. Bardeen, Editor; School Century, Oak Park, Ill., Geo. W. Jones, Editor; School News, Taylorville, Ill., L. L. Parker, Editor; School Science and Mathematics, Chicago, Charles H. Smith, Editor; Sierra Educational News, San Francisco, Cal., Dr. Arthur Chamberlain, Editor; Southern School Journal, Lexington, Ky., R. S. Eubank, Editor; Teachers' Monograph, Jamaica, N. Y.; Texas School Journal, Dallas Texas, H. T. Musselman, Editor; Southern School Work, Alexandria, La. C. R. Reagan, Editor; Utah Educational Review, Salt Lake City, H. R. Driggs, Editor; Western Teacher, Milwaukee, Wisconsin, S. Y. Gillan, Editor; Wisconsin Journal of Education, Madison, W. N. Parker, Editor.

RADIUM LUMINOUS COMPOUNDS.

The use of radium luminous compounds has only recently been recognized in connection with commercial apparatus, but is now widely known through the enormous sale of watches and clocks with "radium dials." It was as recent as 1910 that Marsden made the first measurements of the brilliancy of zinc sulphide under the action of thc radiations from radium products, but it was not until several years later that advantage was taken of this fact to make instruments, which must be read at night, self-luminous.

=

Radium luminous compounds consist almost exclusively of specially prepared zinc sulphide, with which is mixed about four parts per 10,000 of radium bromide or its equivalent in gamma ray activity. To apply the paint, in practice, the powdered material is mixed with a minimum possible quantity of varnish or other suitable binding material, and laid on either with a brush or by filling in the figuring which has been engraved into the surface of the object to be painted. The luminosity of the material is due to the action of a particles from the radium impinging on the crystals of zinc sulphide. The light is of a decidedly greenish hue and in the visible region lies between λ=5,920 and λ=4,250, with a fairly sharp edge toward the red. The degree of brightness is of the order of 10 microcandles per square centimeter, or .03 equivalent foot-candles. This is about one-hundredth of the brightness of a newspaper satisfactorily illuminated for comfortable reading by artificial light. It is of the order of the brightness of white paper illuminated by the light of the full moon. The luminosity of radium compounds falls off with time. The radium itself decays to half its value in about 2,000 years, and it has sometimes been assumed that radium paint will retain its luminosity for a similar period. But this is not the case, for decay is mainly due to action on the zinc sulphide itself, which loses its power to luminesce in the course of time. In general, the material attains a maximum brightness in ten to twenty days after mixing. The intensity then falls off gradually and probably becomes almost constant after a couple of years. Thus we may conclude that a watch dial which is satisfactorily brilliant after a year or two will continue to remain so.

When the material is applied as paint the rate of decay of luminosity is noticeably lower than that of the compound before application, and the initial luminosity is also smaller, being of the order of one-third to onefourth of that of the compound before application. The reason for this is not clear, but it seems reasonable to suppose that the effect of the varnish or other medium is to impede the activity of the a= ray bombardment from the radium, and in this way cause an effective lowering of the radium content of the compound with a subsequent reduction of both the initial luminosity and also the rate of decay.

The initial brightness is in the ratio of the radium content, but the rate of decay of the compound of smaller content is slower, so that the ratio of the luminosities gradually approaches unity as time goes on. This question is of considerable commercial importance, for it is clear that if the compound is required for use after the lapse of several years, there is very little advantage, except from the point of view of initial brightness. in increasing the radium content beyond a certain point. For painted dials the maximum useful content for a life of over six months will not be more than .6 mg. per gram, and the minimum useful content about .2 mg. per gram. The factor of cost cannot be ignored for a compound containing .4 mg. of radium per gram of zinc sulphide costs about $30 to $35 per gram. This is mainly due to the amount of radium present.

This unit is the brightness of a perfectly diffusing surface with a coefficient of reflection of 100 per cent when illuminated to an intensity of a one foot candle, i.e., by a source of one candle placed one foot away.

In the proper training and development of the young mind there are certain fundamental principles which must be thoroughly understood by parent and teacher in order that the youth may receive the instruction in a manner that is practically unconscious to him, and yet in one that will cause him to grasp and appreciate them in such a way that they will become a part of his higher nature. It is the purpose of the writer to present in this code a series of fundamental principles to which an intelligent person can take no exception. These are suggestions which, if presented by a tactful parent or teacher and fully grasped by the child, will drive home truths in such a manner that the young person will absorb them with very little antagonism and will cause him to grow from youth into manhood developing that highest type of citizen, which will be of immeasurable worth both to home and country.

The child should be taught to realize that the parent and teacher are his best and truest friends, and that, that in which they instruct him is for his good and prepares him to meet life's activities.

The habit of cleanliness in all its phases should be urged upon the young mind, as many of the fundamental principles which he should understand are intimately associated with the prin

1One of fifty-seven Codes written by as many persons selected from nearly every state in the Union from the ranks of those known to be successful in the government and education of large groups of boys and girls. The author of this particular Code invites from everyone interested in the proper education and development of the American boy and girl, criticism and suggestions for its revision and improvement. He will thank the readers for a thorough and frank discussion of the merits or demerits of the paper.

ciple of cleanliness, not only of body but of thought and action as well. The degree of morality possessed by these young people is largely measured by their personal appearance, and though we may not go into detail, it is enough to suggest that they must have clean hands, clean nails, clean teeth, and other conditions which will commend themselves to the teacher and parent. These physical characteristics will inevitably lend a strong influence in producing within the young person's mind clean thoughts, from which will come clean speech.

Fundamentally the child should be brought to realize that there is within him a principle of honor which he himself must develop, not only to assure self-respect, but also to merit the respect of his associates. He must, in all of his dealings with his playmates, teachers, or parents, realize that honesty is paramount to any underhandedness that he might conceive would temporarily aid him in securing favor, position, or accumulation of wealth. He should also be made to understand that it is a function of his nature to assist his playmates, especially those who are weaker in mentality or in physical prowess, thus creating within him the spirit of lovableness to such a degree that it will become second nature to assist any who might be in need of help.

The adolescent child should be taught fairness in his play, whether in various recreations or in the game of his home and social life. He must play the game for its worth, and under no circumstances strive to win by any method of an underhanded nature. If in the family there are brothers and sisters, the spirit of filial love should be cultivated to its fullest extent, that they may be mutually helpful, not only within the family circle but in all undertakings where the interests of each or any are at stake.

Love and respect for parents should be of such a deep and abiding type that, whatever the situation, the child will adhere to their teachings. There are times in the life of the young boy and girl when they need a confidant. That confidant should be a parent, or ofttimes a teacher. This highly developed respect for parents and teachers will be one of the strongest faculties in holding the child to that way of living which develops the highest moral character. Honest respect for parents develops respect for neighbors, for the community, and for the property of others.

Respect by precept and example cannot be too early incor