594 



NA TURE 



[October i i, 1906 



iiiittee Report No. 25 deals with errors in workmanship, 

 based on measurements carried out for the committee by the 

 National Physical Laboratory. In order to assist them in 

 the formulation of a system for limit gauges, the com- 

 mittee, in addition to collecting evidence from both manu- 

 facturers and users, carried out a comprehensive series of 

 measurements on actual work, and a record of these 

 measurements is contained in report No. 25, but no system 

 of limits is laid down therein, the recommendations being 

 contained in report No. 27, which deals with British 

 standard systems for limit gauges (running fits). The 

 measurements were carried out on a number of plain 

 cylindrical shafts and holes from 2 inches to 12 inches in 

 diameter. The recommendations based on these measure- 

 ments deal with running fits, and cover diameters of 

 J inch up to 12 inches. It is proposed that the allowance 

 for a running fit shall be made in the hole, and not on 

 the shaft. The standard tolerances and allowances are 

 clearly shown graphically and in tabular form. Four 

 grades of work are provided for, the highest being intended 

 for special cases in which extreme accuracy is necessary. 

 The reports should be carefully studied by all mechanical 

 engineers, and it is to be hoped that the committee will 

 carry its investigations still further, and ascertain whether 

 it is possible to draw up recommendations for standard- 

 ising driving fits. 



A PAPER by Mr. Wilkinson in the current number of 

 the Journal of the Institution of Electrical Engineers, on 

 waste in incandescent lighting, is of particular interest in 

 view of the recent recommendations of the standardising 

 committee in connection with incandescent lamps. Mr. 

 Wilkinson deals very fully with the question, and gives 

 examples of waste due to various causes, and suggests 

 remedies to counteract them. The need for local labor- 

 atories and standardising of the pressure of supply is very 

 strongly insisted upon, and several pressure charts are 

 given which show how irregular the pressure regulation 

 is at various supply stations. Automatic regulators in the 

 generating stations are the author's solution of the latter 

 difficulty, the benefit of which has already been proved at 

 Harrogate, where they are installed. Mr. Wilkinson also 

 finds that " local control " of lamps to be used on the 

 supply mains is effective in ensuring that the lamps sup- 

 plied by the manufacturers are up to specification, and at 

 the same time leaves the contractors the benefit of the trade 

 in lamps. 



Mr. F. Howard Collins has sent us a specimen of the 

 "360° Mariners' Compass Card," designed and registered 

 by him. There is nothing new in the idea of marking by 

 degrees, it having been suggested for use in ships of H.M. 

 Navy so far back as about 1896. But though the plan is 

 a good one, the great difficulty is to get it made universal. 

 Ships nowadays generally do steer by degrees, but the card 

 is marked from N. and S. 90° each way to E. and W. 

 Thus a ship would steer N. 80° W. present style, new 

 style 280°, which would convey very little to a poorly- 

 educated sailor man. As regards compasses in use ashore 

 for surveying and similar purposes, they have been 

 marked to 360° for a very long time ; and the only other 

 markings on the card are the cardinal points, the method 

 of recording being similar to that suggested. The system 

 has much to commend it, and if it could only get generally 

 known there is no doubt its advantages would in time 

 lead to its adoption throughout the fleets of the world. 



The development of certain species of moulds, such as 

 Penicillium and Aspergillus, is shown by B. Gosio in the 

 NO. 1928, VOL. 74] 



Atti del Lincei (vol. xxv., ii., p. 59) to be accompanied by 

 the transformation of carbohydrate into phenolic derivatives 

 containing a closed carbon chain. In certain cases 

 coumarin and its derivatives seem to be formed, which 

 show characteristic colour reactions with alkalis and with 

 ferric chloride. The production of such substances, it is 

 suggested, may prove a valuable means of detecting changes 

 in maize caused by parasitic agency, and a method of 

 diagnosis in cases of pellagra, which is generally regarded 

 as due to the toxic action of substances elaborated in 

 maize owing to the development on it of certain fungi. 



We have received a copy of vol. xix. of the annual re- 

 ports on the advancements of pharmaceutical chemistry 

 and therapeutics, issued by Messrs. E. Merck, of Darm- 

 stadt. The work comprises 260 pages of information of a 

 character sufficiently defined by the title, and supplies a 

 really valuable summary of recent pharmacological re- 

 search. Each substance is dealt with under the heading 

 of its name, the names of the drugs being arranged alpha- 

 betically. A useful index of diseases and symptoms is 

 appended as a guide to the appropriate drugs for their 

 treatment. The fact that particulars are given of the 

 chemical nature and properties of new drugs which have 

 been put on the market with fancy names makes the re- 

 port valuable, not only to the medical man, but to the 

 chemist. The work is sent free to medical men and others 

 interested in pharmacology or therapeutics on application 

 at Messrs. .Merck's London office, 16 Jewry Street. E.C. 



In No. Sj of the Communications from the Physical 

 Laboratory of the Leyden University Prof. H. Kamerlingh 

 Onnes and Dr. W. Heuse describe some experiments made 

 on the coefficient of e.xpansion at low temperatures of 

 Jena and of Thiiringen glass. .'\n ordinary dilatometer 

 method was employed, the temperature of the rods of glass, 

 which were about i metre long, being measured by an 

 appropriate platinum-resistance method, accepting for this 

 platinum the relation between resistance and temperature 

 obtained in experiments described in Communication 

 No. 77, R, = R„ (i-|-o.o03864i — 00000103/-). The steady, 

 low temperatures were obtained by means of liquid gases 

 contained in an ingeniously constructed vacuum vessel open 

 at both ends, into the outer wall of which was sealed 

 about the middle point a kind of " aneroid box," to take 

 up the strains due to the very different expansion of the 

 outer and inner glass tubes. The results of the experi- 

 ments gave for the range —^82° C. to -|-i6° C. the follow- 

 ing values of the coefficients in the ordinary formula for 

 linear dilatation, L, = L„(i + a(-f-j3f=) : — 



For Jena glass 16'", = 7-74x10-°, and /3 = 0-00882 X 10- " 

 For Thiiringen glass, = 9-15x10-', and j3 = o-oii9 X 10-^ 



The authors seem unaware of the experiments by Dr. 

 Travers on the same subject, and their result gives for 

 mean expansion of ordinary glass a value considerably 

 greater than that found by him. 



Among the articles in the current number of the Monthly 

 Revieiv are two dealing with scientific subjects. M. 

 Henryk .Arctowski deals with polar problems and the inter- 

 national organisation for their solution. He first directs 

 attention to the conference held on September 7 in Brussels, 

 when the three questions it is suggested might be solved 

 by international cooperation were discussed, viz. the 

 problem of the North Pole, the geographical problems of 

 the Antarctic regions, and the scientific problems necessi- 

 tating simultaneous expeditions and universal cooperation- 

 M. .Arctowski gives a brief historical sketch of polar re- 



