particularly be of the same design and finish, although the glassware or shades can be different in shape and color.

In other words, in the smaller residences all the fixtures should be as nearly the same style as possible, or the house will look like a second-hand fixture establishment. In large houses, the type of decoration is the controlling element.

In conclusion, I want to call attention to the fact that central station managers are beginning to realize the importance of increasing the residence load. The great variety of house wiring campaigns now under way certainly emphasize this fact and great effort is being made to equip old houses for electric service.

In the territory of the Edison Electric Illuminating Company of Boston alone, there were many thousands of unwired houses before the house wiring campaign was started, and at the end of three years about 4000 of these houses had been wired on the "Easy Payment Plan" with an approximate annual income of $100,000an average of $25 per year, per customer. This means an addition to the lighting load of about 4000 kw. which load, coming as it does on a late peak, is very desirable, a fact that is being appreciated more and more.

THE LIGHTING OF STREETS-PART I

BY PRESTON S. MILLAR

This lecture is to be considered as complementary to that of Mr. Lacombe which is to follow. The two are intended to embrace the entire subject of street lighting. The division between the two is arbitrary and of course cannot be absolute.

HISTORICAL

Within the limitations of time imposed it is not desirable to dwell upon the historical aspects of the subject. The evolution of street lighting from the torch bearing stage through the period of candle and oil lamps, maintained individually by citizens,* up to the beginning of community or municipal maintenance, has little practical bearing.

The modern history of street lighting begins with the invention of illuminating gas and assumes its second interesting phase with the development of the direct-current series carbon arc lamp. Following these two stages of progress, the historical aspects of street lighting naturally ramify into the history of street illuminants, of street lamp mountings, of street lamp equipments and accessories and of the development of ideas of street lighting principles. These several phases of the subject are treated under their respective headings in either this lecture or in Mr. Lacombe's lecture.

PURPOSES

The earliest street lighting was adopted as a measure of protection for the wayfarer against the criminally inclined. At first this purpose was served partially by the carrying of torches.

⚫ Some milestones in the historical progress of street lighting are as follows:

1558-Paris the first modern city to attempt civic street lighting. Inhabitants ordered to hang lighted candle lanterns in front of houses.

1766-Pitch or resin bowls substituted for candle lanterns. 1809-First street lighting by illuminating gas in London.

1821-Illuminating gas used in Baltimore for street lighting.

1884-Arc lamps used in Philadelphia for street lighting.

1896-Gas mantle lamps first used in this country for street lighting.

Then the lamps were placed permanently along the way, affording better protection and also marking the route. From this stage street lighting was evolved into a means of safeguarding traffic against collision and of revealing obstructions or holes in the roadway. More recently it has been developed into an ornate system which not only accomplishes these purposes but also promotes commerce and embellishes the highway both by its own artistic qualities and by the lighting effects which it produces.

Modern street lighting serves the combined purposes which have been named, these being fundamental perhaps in the order in which they are mentioned. The protective element, however, is sometimes taken for granted, and most, if not all, attention is directed to the last purposes named. All street lighting ought to serve these several purposes and the importance of each purpose in a particular installation must depend upon the local conditions, principal factors among which are traffic density, real estate development and criminal hazard. In portions of cities in which evil resorts exist, the police protection factor is of first importance. In interurban highways the marking of the way and provision against collision are essential. The dignified, high-class avenue must be so lighted as to reveal its character by exhibiting to advantage the architectural features of the buildings. For police purposes the lighting should be designed primarily to reveal large objects on the street and sidewalk.

To serve the purposes of the automobilist the same requirement exists, and in addition raised places or depressions in the roadway should be revealed, and the curb or limitations of the driveway should be perceptible. His is the most difficult requirement to meet because of the high rate of speed at which he travels. Safety requires that he must be able to detect the presence of objects in a single glance.

The pedestrian requires somewhat the same lighting design, though he is especially concerned in having inequalities in the sidewalk revealed. In the important streets he should be able to distinguish faces of passers-by.

From the point of view of æsthetics the fundamentals of design in all visible portions of the lighting system should be observed. This applies especially to posts, fixtures and glassware. The incongruous should be absent; nor should the general effect of the street be neglected. The fixtures should be of pleasing design in themselves and suitable to their surroundings. They should be installed at such intervals and in such locations as to enhance the attractiveness of the street by day and by night.

Minor requirements of street lighting present themselves. For example, one may wish to observe the time indication of his watch, or to read an address on a card, or to find an article which he has dropped, or to read a number on a house front. All such requirements are distinctly minor and should not have an important place in a discussion of this kind. Many of them can be met by moving near to a street lamp; others occur so infrequently as not to demand much consideration. In general, lighting which serves the major purposes outlined above serves also these minor purposes as well as they can be served with a given expenditure for lighting.

All of the foregoing may be summed up in a statement of the purposes to be served by street illumination put forward by the Street Lighting Committee of the National Electric Light Association in 1914 as follows:1

1. Discernment of large objects in the street and upon the sidewalk.

2. Discernment of surface irregularities on the street and on the sidewalk. 3. Good general appearance of the lighted street.

In studying the street lighting requirements for a particular locality, much time and thought profitably may be devoted to defining for that locality the principal purposes of the street lighting. With these purposes clearly in mind, best efforts are more likely to be made to design the installation in conformity with the requirements. Most serious mistakes in the design of street lighting have occurred because those responsible have failed properly to analyze the purposes to be served by the lighting and have proceeded in design without sufficient thought or according to preconceived ideas of the requirements of good street lighting. It is almost as unreasonable to design street lighting without reference to the local requirements as it is to design interior illumination without reference to the character and decorations of the room.

EXTENT AND SCOPE

Street lighting is regarded as one of the indispensable functions of municipal government. As a rule in this country it is rendered by a private corporation under contract with the municipality. Cities, towns, and even the smallest villages are lighted very generally. It has been stated that the lighted streets of New York City alone, if placed end to end, would form a single lighted highway extending from New York to Reno, Nevada.