August 8, 1895J 



NATURE 



55; 



flame, with the resuh that in those series of experiments in 

 which the height of the pentane air-gas flame was adjusted 

 strictly according to the directions given in the Appendix, the 

 light afforded by this flame was found to agree exactly with the 

 mean result afforded by the standard candle flame. In other 

 series of experiments, indeed, in which a slight variation was 

 made in the mode of adjusting the height of the pentane air-gas 

 tlame, some discrejiancies in the direct results furnished by the 

 comparison of its light with that of the standard candle flame 

 were observed ; but in these several series of exjieriments also, 

 when the necessary correction, called for by the difference in 

 the mode of adjustment resorted to, was made, the light of the 

 pentane air-gas flame was found to accord closely with the mean 

 result afforded by the standard candle flame. 



"(7) Inasmuch, however, as there is a practical advantage in 

 comparing directly the light of such a coal-gas flame as is usually 

 tested (being, that is. of about a sixteen-candle-light value), with 

 a light apjiroximating somewhat in value thereto, we have further 

 submitted to carefid examination the flame of the ten-candle- 

 light pentane argand proposed as a standard by Mr. W. J. 

 I )ibdin in iSS6. This flame is produced by burning a mixture of 

 air and pentane vapour from a suitable argand burner, provided 

 with an opaque screen by which the light from the upper [portion 

 of the flame is cut ofl'. The screen being set at a definite height, 

 it was found by .Mr. Dibdin that, owing to a compensating acticm 

 affecting the lower or exposed portion of the flame, th^ luminosity 

 of this portion of the flame remains constant even under con- 

 siderable variations, whether in the ttital height of the flame or 

 in the jiroportion of pentane vapour to air in the mixture burnt. 

 With a view to simplify the construction of the argand burner 

 furnishing a cut-off flame of this constant luminosity, we have 

 tried various changes in the form of the cone and in the division 

 ^^f the air supply to the flame, but in every case have found the 

 original burner, as su]iplied by Mr. Sugg for the purpose, to give 

 more satisfactory results than the modified forms. 



" (8) The amount of light emitted by the portion of the 

 I )ibdin argand pentane-air flame that is used in photometry, being 

 depeiulent on the distance above the steatite ring of a screen by 

 which the u]iper part of the flame is cut ofli, we have come to the 

 conclusion that when the bottom of the screen is fixed at a height 

 ■ if 2'15 inches (54"6 mm.) above the lop of the steatite ring, the 

 amount of light emitted by the lower portion of the flame is sub- 

 stantially equal to ten times the average light of a standard 

 sperm candle flame, or to ten limes the light of Mr. Harcourt's 

 one-candle-light pjntane air-gas flame. 



" (g) We have further satisfied ourselves that any number of 

 Dibdin argand burners may be produced, having the form and 

 dimensions set forth in the Appendix ; and that these several 

 burners, when useil in the manner there defined, may be 

 depended on to furnish a flame giving, when duly sceened on 

 the top, ten times the average amount of light given by a 

 standard sjierm candle. 



"(10) We therefore recommend that the pentane-air flame 

 furnished by a Dibdin argand Ijurner, having the form and 

 <limensions set forth in the A])pendix, and used in the manner 

 there defined, be accepted as giving the light of ten standard 

 ■candles, and that this flame be authorised and prescribed for 

 ofticial use in testing the illuminating power of the gas supplied 

 by the I.ondcm (las Companies. 



"(II) We further recommend that sealed specimens of the 

 Inirner, the carburetter, and the pentane for use therewith, duly 

 ■certified by the Gas Referees, be deposited with the Board of 

 Trade, anti also in such places and in the care of such persons 

 as the Hoard may direct, to be available for the purpose of com- 

 parison, in the event of any question arising as to whether the 

 1ientane-air flame of some jjarticular burner does or iloes not 

 afford the same amount of light as that now proposed for 

 adoption as a standard. 



"(12) With a view to making some provision for future pos- 

 sible improvements and requirements, we further recommend 

 that the Gas Referees be authorised, should they at any time see 

 fit, to approve and certify for use in g.as-testing any other flame 

 based u|ion the locandle standard defineil above, which they may 

 consider suitable for the purpose, whether produced in a like or 

 unlike w.ay, and whether having the same or a different multiple 

 value ; such other flame, however, not to be used for g:is-tesling 

 unless approved by the Board of Trade, and unless the Gas 

 Companies give their consent to its adojition as a standard. 



"(13) We further recommend that the Illuminating power of 



NO. 1345, VOL. 52] 



coal gas shall continue to lje recorded as heretofore in terms of 

 the light given by a specified number of cubic feet (to wit, 5 

 cubic feet) burnt per hour from the standard London argand 

 burner, but that, in testing the illuminating power of the gas, 

 the requirement that the gas shall .actually be consumed at this 

 rate be rescinded, so as to allow the (Jas Referees to sanction a 

 mode of testing in which the gas shall be burned from the 

 standard London argand burner at whatever rate is found 

 requisite in order that it may give a light equal to that of the 

 prescribed number of candles, and in which the illuminative 

 value of the gas shall be calcidated as being inversely as the rate 

 at which such gas had to be burned during the testing so as to 

 give this amount of light." 



The Report is signed by Prof. William Odling, F.R.S. 

 (Chairman), Mr. W. J. Dibdin, Dr. E. Frankland, K.R.S., 

 Dr. A. Vernon Harcourt, F. R.S., Mr. (leorge Livesey, 

 Dr. William Pole, Mr. Cleorge Rose-Innes, Prof. A. W. Riicker, 

 I'.R.S., Dr. W. j. Russell, F.R.S., Mr. (,. C. Trewby, and 

 (subject to the omission from (13), line 7, of the words " the Gas 

 Referees to sanction ") by Mr. II. E. Jones. Prof. Vinan B. 

 Lewes was the Secretary of the Committee. 



SCIENTIFIC EDUCATION IN AMERICA. 



T T PON the occasion of the laying of the corner-stone of a new 

 ^ building for a Museum for Dartmouth College, Hanover, 

 U.S., Prof. A. .S. Bickmore recently delivered an address, in the 

 course of which he dealt with the methods of .scientific 

 instruction in .Vmerica. The College was originally designed 

 to elevate the Indian race in America, hence its location at 

 Hanover, New Hampshire, in 1770. It was named after Lord 

 Dartmouth, who took a deep interest in the aborigines of the 

 New World, and who was the principal benefactor of the 

 school established for their education. 



We extract the following from the report of Prof. Bickmore's 

 address in the Nciu York Times : — 



"The present is pre-eminently an educational age, and the 

 princely gift from one of our alma mater's loyal sons for the 

 purpose of endowing a ' professorship of pal.eontolog)-, arche- 

 ology, ethnology, and kindred subjects, and for the erection of a 

 building for preserving and exhibiting specimens illustrating the 

 aforesaid branches,' is in perfect harmony with the judgment of 

 the leading educators of our times, namely, that the greatest 

 benefit it is our privilege to confer upon coming generations is to 

 provide ever-incre.ising means for their mental improvement. 



" As we meet to-day to lay the corner-stone of the noble edifice 

 so generously provided for by the late Dr. Ralph Butterfield, 

 and to celelirate the commencement of a structure which will 

 add so largely to the educational facilities of this college, I invite 

 you to consider with me, as a subject suggested by this occasion, 

 ' The Place in Modern Education of the Natural Sciences and 

 their Museums.' 



" In a period which will ever be famous in history for the great 

 donations that are being constantly made by our private citizens 

 for the public good, it is worthy of our careful consideration 

 that the most munificent gifts are almost exclusively for the 

 purpose of promoting education. In the United States where, 

 even the existence of ' a Government for the people and by 

 the people ' must ever rest upon the intelligence and the 

 integrity of each individual citizen, it is not a matter of desir- 

 ability, but simply one of necessity, that the promotion of public 

 instruction shall ever be a question of paramount importance. 



American System of Te.xchinc. 

 " Our American system of instruction may be rajiidly sum- 

 marised. First and lowest is the kindergarten, which may be 

 regarded as still in its experimental stage, but which is certainly 

 destined to become one of our most effective methods of mental 

 training. Next come the public schools, supjKirteil by taxation, 

 with their primary .and grammar gr.ades, and the high schools 

 and ])rivate academies. Above these are the colleges, with their 

 ever-increasing series of elective .studies ; and then the univer- 

 sities, with their special schools of science, meilicine, law, .and 

 theology ; and finally, the great post-graduate institutions, 

 composed of entirely di.slinct corporations for the creation of 

 great museums of science and art, and the accmnulation of 

 exhaustive libraries. 



