412 



SCIENCE. 



[N. S. Vol. XVI. No. 402. 



catalogued and assigned to duty, the plan 

 is revised to nialie sure that every step in 

 its series of proposed tasks is provided 

 with the needed apparatus and material, 

 direct and accessory. The scheme of the 

 work may then be written out in full, and 

 the memorandum should include a refer- 

 ence to the apparatus selected for use at 

 every su.ecessive step and a statement of 

 the kind and quantity of material to be 

 provided. The materiel of the campaign 

 may next be assembled or, if extensive, 

 located, and its availability assured. It is 

 sometimes embarrassing to reach an im- 

 portant point in such work and to find that 

 a piece of apparatus or certain material 

 needed, possibly immediately and impera- 

 tively, is not to be had. It may be neces- 

 sary to set about tlie design and construc- 

 tion of special apparatus at once in order 

 that the investigation shall not be delayed 

 at a later stage by its non-completion. 



My own expei'ience yields an illustration 

 of this point. I had been intrusted with 

 the exploration of the whole field of those 

 ternary alloys of most importance in the 

 arts, those of copper, zinc and tin, the 

 'kalchoids,' as I called them, and could see 

 no way of systematically and economically, 

 yet completely, accomplishing what seemed 

 the impossible task of determining the 

 strength, elasticity, ductility and other 

 properties of the useful alloys in all the 

 infinite number of possible compositions. 

 The task proved simple, easy and inex- 

 pensive, comparatively, when I had, after 

 some months of delay awaiting a satisfac- 

 tory scheme, hit upon the system of plan- 

 ning the representation of the results of re- 

 searches involving such measurements of 

 three coordinate dimensions.* To-day, the 



* ' On a JNIethod of Planning Researches involv- 

 ing Three Dimensions,' Transactions of the 

 American Association for the Advancement of 

 Science, 1877. ' Strongest of the Bronzes,' 

 Transactions Am. Soc. C. E., 1881. 



principal characteristics of that whole class 

 of useful alloys are not only determined, 

 but are represented by graphic and glyptic 

 and algebraic forms permitting their com- 

 putation or measurement, whatever the 

 alloy sought. 



The outcome was also, as obviously might 

 have been prophesied, the identification of 

 what I denominated the 'maximiun alloy' 

 — the strongest alloy that man can make 

 by combination of those three metals — its 

 composition, its strength and its every 

 important characteristic. An alloy which 

 has been on the market now for many years 

 and has proved to be of extraordinary 

 value is one of these 'kalchoids,' closely 

 approximating the 'maximum alloy' in its 

 proportions and properties. 



By patiently waiting until a satisfactory 

 system could be adopted, it thus became 

 possible to select intelligently a few repre- 

 sentative alloys and by the results of their 

 examinations construct the curve or the 

 surface, the diagram or the model, of which 

 the ordinates should give the values of the 

 characteristic by them measured of all pos- 

 sible alloys of the metals employed, whether 

 the alloy be binary or ternary.* 



One of the best illustrations of the scien- 

 tific method of planning the investigation 

 of an as yet unexplored field, and of the 

 endeavor to discover a method of utilization 

 of as yet undiscovered means of obtaining 

 a desirable and defined result, is the case of 

 the invention of the new general method of 

 production of aluminium. 



The investigator was an undergraduate 

 student at Oberlin. He recognized the 

 probable value of aluminium in the arts, 

 could it be produced in large quantity for 

 market and at a low cost. He believed 

 that electrolysis would prove the most con- 

 venient, perfect and inexpensive method; 



* ' Graphic Diagrams and Glyptic Models ' ; R. 

 H. Thurston, Transactions As. M. E., Vol. XIX., 

 1898. 



