132 



SCIENCE. 



[Vol. XI. No. 267 



A Text-Book on Roofs and Bridges. Part I. Stresses in Simple 

 Trusses. By iViANSFlELD Merriman. New York, Wiley. 

 8°. $2.50. 



This work of Professor Merriman exhibits in a remarkable de- 

 gree the clear, logical arrangement and concise style which charac- 

 terize his writings on engineering and mathematical subjects. 



The preparation of suitable te.xt-books of applied science, and es- 

 pecially text-books on engineering subjects, for students of technical 

 schools, at the present day, is an art that demands something more 

 than a critical knowledge of the subjects discussed. It involves 

 also, in the highest degree, a true conception of the art of teaching; 

 and it may almost be laid down as a rule that the most successful 

 teacher is best fitted to prepare a text-book on the subject which 

 he teaches. 



Admirable works there may be on particular branches of engi- 

 neering : for example, works in which abundance of detail and 

 lillustration, the presentation and solution of intricate and unusual 

 problems, and the introduction of whatever may elucidate the sub- 

 ject, furnish to the investigator or professional engineer most valu- 

 able and instructive information, but which may be quite unsuitable 

 for the daily use and instruction of the undergraduate student. 



During the period of the life of a student when his habits of 

 thought and investigation are forming, it is of the utmost impor- 

 tance that he should become thoroughly imbued with the rational 

 principles and processes of thought which will make him an inde- 

 pendent thinker and investigator. 



In this work the plan adopted for the computation of stresses in 

 the members or parts of roofs and bridges, is, to use Professor 

 Merriman's own words, "The principles and methods are first 

 ■established, and then numerous examples are fully worked out to 

 illustrate them and their application to different forms of trusses, 

 while a number of problems are stated for the exercises of stu- 

 dents." 



This plan is faithfully carried out, the mathematical treatment of 

 the principles and methods being clear and concise, and free from 

 -complications. 



Professor Merriman's work on the ' Mechanics of Materials,' in 

 the same style, and with similar arrangements, was unsatisfactory 

 ■ only in this, that it seemed to end in the middle of the subject, 

 trussed or braced structures being left out ; but the addition of the 

 present work supplies the deficiency, and the two together will now 

 •constitute a complete work, admirably adapted to use in the higher 

 technical schools. 



Heport of the Commissioner of Education for 1885-86. Wash- 

 ington, Government. 8°. 

 This report is the first issued by the new commissioner, Mr. 

 Dawson, and is nearly, if not quite, as far behindhand in its appear- 

 .ance as its predecessors. We believe that the blame for this is to 

 'be laid at the door of the Government Printing-OfFice, at present the 

 most inefficient department of the public service. In arrangement 

 at is far superior to the bulky and confused reports issued by Mr. 

 Eaton. The classification of the statistics, and their mode of treat- 

 ment, mark a decided advance on what we have been accustomed 

 to. The summary of State school laws is a valuable feature, as are 

 the particularly useful statistics in Appendix X,, dealing with edu- 

 ^;ation in foreign countries. This report, though good and useful, 

 shows by its failures how essential some revision of the method of 

 -classifying educational statistics is. It is the task of a lifetime to 

 •extract from them, as at present presented, any answers to a score 

 of pressing and important questions. The commissioner of educa- 

 tion should have the power to inaugurate and carry through this 

 -much-needed reform. 



.Elizabeth Gilbert and her Work for the Blind. By FRANCES 

 Martin. New York, Macmillan. 12°. 

 The subject of this biography was the daughter of the principal 

 ■of Brasenose College, Oxford, afterwards Bishop of Chichester. 

 She was born in 1826, and was made blind at the age of three by 

 .an attack of scarlet-fever ; but she was a girl of more than usual 

 intelligence and energy, and, under careful instruction, became a 

 'vvell-educated woman, knowing French, German, and Italian, as 

 (ivell as vocal and instrumental music. She learned also to write a 



very legible hand ; but written arithmetic was difficult for her. 

 though she reckoned easily and accurately in her head. 



During her childhood and youth she was always treated, both in 

 her studies and in her plays, as nearly as possible like her sisters ; 

 but when she became a woman, and her sisters one by one mar- 

 ried and left home, she began to feel her loneliness, and especially to 

 feel that there was no field of usefulness open to her. But having 

 received a legacy from a lady friend, which made her pecuniarily 

 independent, she soon discovered work to do. She saw and keenly 

 felt the difficulties that blind persons have in getting employment, 

 even if they have learned a trade ; and she undertook to furnish 

 such employment, so far as her resources would permit. She first 

 opened a store for the sale of goods made by the blind, employing 

 a blind man as manager, she herself assuming the pecuniary re- 

 sponsibility, and meeting all deficiencies at first out of her private 

 purse. To the store a factory was soon added, and the whole 

 placed in charge of an association, which ultimately developed into 

 The British Association for promoting the General Welfare of the 

 Blind. Miss Gilbert was also active in serving the cause of the 

 blind in other ways, so far as she had opportunity to do so ; but we 

 must refer our readers to the biography itself for the details of her 

 work. She died in 1885. This story of her life is well and simply 

 told, and we commend it to those who are interested in philan- 

 thropic work. 



The Orbis Pictus of John Ames Comeniiis. Syracuse, Bardeen. 

 8°. 

 It gives us a startling conception of the antiquity of Harvard 

 College to recall that this educational classic, which so many per- 

 sons associate with the middle ages, was written by a man who 

 was solicited to accept the presidency of that institution. Mr. Bar- 

 deen deserves the hearty thanks of all educators for reproducing 

 the famous work, and issuing it at a reasonable price. The paper, 

 the binding, the type, are all appropriate. The cuts are unusually 

 clear, and are taken from the copperplates of the edition of 1658 ; 

 the Latin text is taken from the same edition. The text for the 

 English translation is taken from the English edition of 1727, in 

 which for the first time the English words were so arranged as to 

 stand opposite their Latin equivalents. The cuts are here repro- 

 duced by the photographic process, and are not retouched or altered 

 in any particular. We trust the Vestibnlum and the Janua may 

 be similarly reproduced at an early day. 



Modern Theories of Chemistry. By Lothar Meyer. Tr. by 

 P. Phillips Bedson and W. Carleton Williams. London, Long- 

 mans, Green, & Co. 8°. 

 While editions of ' Die Modernen Theorien der Chemie'have 

 succeeded one another in the original to the number of five, 

 the English-speaking public has waited more than a score of 

 years the opportunity to read in the vernacular a work which, 

 perhaps more than any other of the period, has been influential in 

 broadening and harmonizing the ideas of chemists as to the mean- 

 ing and connection of the throng of facts which busy workers have 

 amassed. The first edition of this work was projected and issued 

 a quarter of a century ago with the purpose of bringing about just 

 valuations of the theories and hypotheses then in vogue but variously 

 estimated, and of showing the suggestive importance of working 

 hypotheses to investigators. The reception of the edition was such 

 (though the author was so modestly diffident of success, previous 

 to publication, as to abandon a personal dedication which ha;d been 

 determined upon) that two more were published in the same form : 

 and a fourth, revised and rewritten to meet the requirements of the 

 time, was issued, only to be succeeded immediately by the fifth 

 edition, upon which the translation now before us was based. In 

 its present form, the book has assumed more of the character of a 

 handbook or book of reference, and on that account the absence of 

 an index is the more to be regretted. Of works merely elementary, 

 and devoted to the representation of accepted theories without ver)' 

 much balancing of the evidence which has led to their establish- 

 ment, we have in English several very good examples ; but with a 

 single exception (Muir's ' Principles of Chemistry '), and that of 

 comparatively recent production, there has been no work on theo- 

 retical chemistry, accessible to the student whose only language is 

 English, of any thing like the breadth of this. Its plan embraces 



