ii6 



NA TURE 



[May 31, 1900 



Master of the Clothworkers' Company, and the completed 

 buildings were opened on May 11. 



At the present time, therefore, the dyeing department of the 

 Yorkshire College is represented by a building of considerable 

 dimensions, and so comprehensive in character and equipment 

 as practically to meet every requirement for the purpose of 

 giving a complete theoretical and practical instruction in the art 

 of dyeing in all its branches. 



Some idea of the magnitude of the work done in the dyeing 

 department of Yorkshire College may be gained from the fact 

 that each session over 200,000 dyed patterns are distributed. 

 Each student, according to the time spent in the dyehouse, 

 receives during his course of instruction from 2000 to 20,000 

 patterns, each of which conveys a definite piece of information 

 on some point connected with the application of this or that 

 colouring matter. Not only is the behaviour in the dyebath of 

 each colouring matter investigated, but notes of the results 

 obtained are made by the students during the progress of the 

 work. Further, each student enters in his own book all the 

 patterns received, together with notes of the materials employed, 

 and the results of each experiment. Hence the students not 

 only learn how to experiment and discover the capabilities of 

 each colouring matter for themselves, but they also acquire the 

 useful habit of observing and of making notes, while their 

 pattern books contain a fund of information which is invaluable 

 to them in their after career. The systematic training which 

 they receive also prepares them to deal with the variable con- 

 ditions of work in actual practice, such as the character of the 

 water, the nature of the textile material employed and its 

 ultimate uses, and many other points which must always be 

 taken into account in dyeing. 



In the practical and pattern dyehouses the students are 

 shown how they are expected to apply in practice the principles 

 they have learned in the course of their experimental work. 

 Moreover, the solution of difficulties which naturally arise under 

 the slightly altered conditions from those obtaining in the 

 experimental dyehouse, the greater confidence inspired by 

 dealing with the larger quantities of material, and the knowledge 

 that the products of their labour are really to be employed in 

 the manufacture of cloth, are all factors of inestimable value in 

 the training of the students before they enter into actual practice, 

 to which they are as it were brought indeed one step nearer by 

 the character of the work pursued. Altogether, the students 

 are able, in the College dyehouses, to gain at least some insight 

 as to the meaning and value of practical experience, and an 

 influence is exerted which reacts by giving life and vigour to the 

 work of the whole department. 



The art of dyeing owes much to science, and in a University 

 College like the Yorkshire College, it is not unreasonable to 

 expect that students of the art should, in return, contribute 

 something to science, more particularly to that branch of it 

 which pertains to dyeing. If in the experimental and practical 

 dyehouses the students are taught the art of dyeing, in the 

 Clothworkers' Research Laboratory they are also urged to study 

 the science of dyeing. The aim here is to assist in the work of 

 gaining a fuller and truer knowledge of the fundamental laws 

 and principles connected with dyestufifs and dyeing, and so help 

 to raise, as far as possible, the whole tone and level of the 

 dyeing trade, by infusing into it the traits of an exact science. 

 The carrying on of original research by advanced students has 

 already become, indeed, a marked feature of the department, 

 and the Clothworkers' Company have, in a special way, recog- 

 nised the value of such work by establishing a lectureship, the 

 holder of which devotes his whole time to co-operating with the 

 professor in introducing students to this higher form of study. 



This research work, too, has an intimate connection with 

 Prof. Hummel's lectures, in the course of which are described 

 the methods employed in preparing the coal-tar colours, in 

 isolating the pure colouring principles of dyewoods, and in 

 studying the chemistry of mordanting, dyeing, &c. By allowing 

 the students to carry out similar experiments themselves, the 

 College enables them to understand, in a clearer manner than 

 is otherwise possible, how our knowledge concerning dyestuffs 

 and dyeing has been acquired, and it is hoped that by reason of 

 the practical experience thus gained in the art of research, some 

 students may, in due time, become independent investigators. 



The Clothworkers' Research Laboratory is an addition which 

 gives completeness to the means of instruction in dyeing already 

 lurnished. The advanced students are thereby provided with 

 the facilities for extending the boundaries of science connected 



with dyeing, and it is hoped that many young men will take 

 advantage of the opportunity thus given. If in the pursuit of 

 this object the authorities at Yorkshire College can succeed in 

 attracting and training a band of earnest workers ; if a well- 

 recognised and successful School of Research in Dyeing is 

 established, side by side with the School of Practical Dyeing, 

 it cannot but be of inestimable value from an educational as well 

 as from a practical point of view, for, if the students, before 

 they leave the College, are taught to contribute to the general 

 sum of knowledge it it surely education in the truest and best 

 sense of the term. 



MR. NIKOLA TESLA'S RECENT ELECTRICAL 



EXPERIMENTS. 

 A REMARKABLE paper, by Mr. Nikola Tesla, appears in 

 ■^ the June number of the Century Magazine. The subject 

 is "The Problem of Increasing Human Energy, with Special 

 Reference to the Harnessing of the Sun's Energy" ; and though 

 metaphysical and sociological questions receive a large share of 

 attention, the article contains an account of some very interest- 

 ing electrical experiments, now described for the first time, 

 illustrated by several very striking photographs, two of which 

 are here reproduced. Mr. Tesla has been engaged for several 

 years in further investigating the properties of alternate currents 

 of high potential and frequency, with which he astonished 

 audiences at the Royal Institution in 1892 (see Nature, 

 vol. xlv. p. 345). The following abstract of a part of his paper 

 shows that his work has led to results of scientific interest and 

 significance. 



Electrical discharges capable of making atmospheric nitrogen 

 combine with oxygen have recently been produced. Experi- 

 ments made since 1891 showed that the chemical activity 



Fig. I. — Combustion of atmospheric nilrogen by the discharge ot an 

 electrical oscillator giving twelve million volts and alternating 100,000 

 times per second. The flame-like discharge shown in the photograph 

 measured 65 feet across. 



of the electrical discharge was very considerably increased 

 by using currents of extremely high frequency or rate of 

 vibration. This was an important improvement, but prac- 

 tical considerations soon set a definite limit to the progress in 

 this direction. Next, the effects of the electrical pressure of 

 the current impulses, of their wave-form and other characteristic 

 features, were investigated. Then the influence of the atmo- 

 spheric pressure and temperature and of the presence of water 

 and other bodies was studied, and thus the best conditions for 

 causing the most intense chemical action of the discharge and 

 securing the highest efficiency of the process were gradually 

 ascertained. The flame grew larger and larger, and its oxidising 

 action more and more intense. From an insignificant brush- 

 discharge a few inches long it developed into a marvellous elec- 

 trical phenomenon, a roaring blaze, devouring the nitrogen of 

 the atmosphere and measuring sixty or seventy feet across 

 (Fig. i). The flame-like discharge visible is produced by the 



NO. 1596, VOL. 62] 



