February 1, 1921 



THE INDIA RUBBER WORLD 



329 



Artificial Lighting in the Rubber Industry — IP 



The Fundamental Principles of Illumination (Physical) 



By E. Leavenworlh Elliott 



WHOSE BUSINESS IS IT TO PRESCRIBE THE LIGHTING? 



BEFORE proceeding to discuss the scieutilic laws and theories 

 pertaining to the use of light for purposes of illumination, 

 it will be well to consider the subject briefly from the per- 

 sonal standpoint. To put the question in its plainest terms : 

 Whose particular business is it to study the lighting problem, and 

 prescribe the kind of illumination to be used? 



The present lack of unanimity on this point is as remarkable 

 as it is general. "What is everybody's business is nobody's busi- 

 ness," is the nearest answer under existing conditions. The light- 

 ing in most factories is a mere inakeshift; it is either an incon- 

 gruous growth from an antiquated installation, or an arrange- 

 ment laid out on empirical rules without regard to the special 

 conditions under which it is to be used. Which of these two types 

 is in use will generally depend upon the age of the buildings. 



New buildings are usually turned over to the owners with tlie 

 lighting equipment installed. Such equipment may be called the 

 blue-print systems of illumination. They consist ordinarily of a 

 certain conventional type of lighting unit distributed in geometri- 

 cal order over the ceiling, no consideration being given to location 



in the lighting problem in its broader aspects, which far exceed 

 the mechanical and electrical boundaries of his professional 

 duties. In such case he will probably pick up considerable 

 practical knowledge from the more observing operatives, 

 and so be able to give really helpful advice on the subject. 

 But such help as he may be able to give is wholly gratuitous ; the 

 knowledge and duties of the electrical engineer do not give him 

 any ex ofljcio control over the methods of lighting. He has dis- 

 charged his full duty when he supplies and maintains such light- 

 ing units as are demanded, in the locations designated. 



Much less often, the purchasing agent assumes the authority 

 of selecting the kind of lighting apparatus to be used — a modern 

 instance of following Hamlet's instruction to "assume a virtue 

 if you have it not." The absurdity of the case only shows the 

 limits to which neglect of this vital facility may extend. The 

 purchasing agent, in his own proper element, asks only the one 

 universal question, "How much?" To buy lighting equipiucnt on 

 a sole basis of first cost is exactly on a par with hiring responsible 

 executives on a basis of salary only — which is enough said on this 

 point. 



High Candle-Power Filament Lamp. 



Luminous Source. Heavy Lines F, 



A Circle GnE'Incii Diameter 



Cooper-Hewitt Mercury Lamp, Luminous Source. Vapor in Glass Tube, One-Inch 

 Diameter, Fifty Inches Long. Insert, Filament-Lamp Using Same 

 Current and Reduced to Same Scale 



of machinery, benches, or operative's position. "Blue-print light- 

 ing" is the result of the problem being handled by the architect 

 or construction engineer. And again I disclaim any intention of 

 reflecting upon the ability of either of these practitioners in their 

 own proper spheres; the only criticism in this case being that 

 they have assumed jurisdiction over a matter with which they 

 have no logical connection. Having assumed jurisdiction, re- 

 sponsibility for results follows, and the results are very generally 

 bad. 



Again, the light being produced from electricity, the whole mat- 

 ter is often turned over to the electrical engineer, whose business 

 it is to install and maintain the electrical equipment. This may 

 produce results having varying degrees of good and evil. H it is 

 simply a matter of initial equipment it will result in a "blue-print 

 lighting" system. If it involves maintenance, it may result in a 

 system chosen wholly with regard to cost and trouble of upkeep, 

 which is fundamentally wrong from the standpoint of rational 

 economics, as 1 have already shown. On the other hand, the 

 electrical engineer, especially if he is the regular works engineer 

 and not acting in a consulting capacity, may become interested 



^ConthiTied from The India Ruui^er World. January 1, 1921. pages 239-241. 



Sometimes the chief executive is the dictator of the lighting 

 equipment. This may occur in "one man" institutions by reason 

 of financial control ; or it may result from the type of personality 

 that insists on being "the whole procession and the dog under the 

 wagon." In any case the lighting will suffer, either from lack 

 of sufficient personal study of the problem, or from time-worn 

 prejudice?, or both. The exceptions will be those small, self- 

 contained concerns whose entire activities are within the intimate 

 supervision of a single individual. 



LIGHTING NOT AN ENGINEERING PROPOSITION 



"I see what you are driving at. You want all the lighting 

 turned over to illuminating engineers." 



My dear sir, never did you guess wider of the mark, .^fter 

 nearly a quarter of a century of work and observation in this 

 field, I am now convinced that industrial lighting is not, properly 

 speaking, an engineering proposition. The net results of all 

 efforts to this end have been to encumber the subject with a 

 mass of mathematical formulas and mechanical details, by the 

 manipulation of which, it is assumed, the proper prescription for 

 the lighting in any given case may be derived. 



Neither experience, nor a comprehensive study of the underlying 



