There were 40,136 street lamps in service in Chicago on January 1 of this year, 38,240 being the average throughout the year, as is shown below: double those in Chicago, as most public utility employes are not paid as high a scale of wages. Chicago's investment per arc light on the AVERAGE LIGHTING EQUIPMENT AND TOTAL COST IN CHICAGO FOR THE YEAR 1913 15,930 450-watt, municipal arcs, at $56.13 1,772 80-watt, series tungstens, at $22.62. 12,769 municipal 50-c. p. gas lamps, at $20.64. 907 rented, 450-watt arcs, at $75.00.. 6,580 rented, 60-c. p. gasoline, at $31.25. 282 rented, 20-c. p. tungsten subway lights, at $6.00. Take the largest item of 17,493 450-watt municipal arcs at an average of $56.13 as an example of what has been accomplished in Chicago by purchasing electrical energy from the Sanitary District of Chicago (a municipal corporation) and operating a municipally owned distribution lighting system. The total cost of $56.13 per arc per year consists of $31.32 cash costs and $24.81 fixed charges, which includes interest, depreciation, taxes and rent. The cash costs of $31.32 per arc lamp per year are made up as follows: $894,150.90 40,082.64 263,552.16 68,025.00 205,625.00 1,692.00 $1,473,027.70 underground distribution system amounts to approximately $510.80, while for the overhead lighting arc system it is approximately $215.60 per arc, making an average investment of $256 per arc for the system. I know of no electric utility corporation paying so high a scale of wages as the city of Chicago for operating and maintaining its lighting system, and yet other cities operating under similar local conditions generally pay 40 to 50 per cent higher rates. The city of Chicago makes yearly contracts with the Commonwealth Edison Company for 450 watt flaming arc lamps at $75 Sanitary District power, including the operation of substations. Totals.. It is very evident from the above items that the electrical energy, which amounts to 36.6 per cent of the total cash cost, is being supplied at a relatively low rate, while the operating labor, 42.2 per cent of the total, is relatively high compared with that of most cities. The electrical energy is contracted for at $15 per horse-power per year delivered to the substations, which, under our operating conditions, means approximately 1⁄2 cent per kilowatt hour. A high union scale of wages is paid all municipal electrical workers in Chicago, including linemen at $5 per day, arc lamp trimmers $100 per month, and line repairers at $155 per month. A study of these factors which make up the cash costs leads one to believe that there should be no reason for cities contracting with electrical utility companies for 450-watt arc lamps at $90 to $100 per year, unless the fixed per year for the outlying districts where the lamps are sparsely installed (averaging 500 feet apart), requiring greater investment and higher annual maintenance costs than if spaced an average of 250 feet apart, as are the municipal arcs. Of the 17,493 municipal arcs (the highest number in use during 1913), 10,044 were of the 10-ampere, flaming arc type; 1,261 were 9.6-ampere, open arcs; and the remaining 6,188 were 7-ampere, enclosed carbon arc lamps. The 1,261 open arcs have lately been replaced by 300-watt nitrogen tungsten lamps. Nitrogen Tungstens vs. Flaming Arcs About six months ago, after a thorough investigation, we decided to discontinue installing 450-watt flaming arc lamps and to install in their stead 20-ampere, 300-watt nitrogen tungsten lamps. The favorable results obtained so far from the 1,800 which believe that this 300-watt, 600-candle-power nitrogen tungsten lamp-which gives an equivalent illumination to that of the 450watt flaming arc after the flamer has been in service a short time-is the most economical high-power open street illuminant on the market to-day. When the slagging of the carbons and the etching of the inner globe of the flaming arc are eliminated, the arc should be a strong competitor of the nitrogen lamp. The nitrogen lamps, which are purchased under a guarantee of 1,000 hours' life, make a more flexible operating system, give a more uniform light and cost less to install and maintain under our Chicago local conditions. It is planned to replace within the next two years the 6,188 7-ampere 450-watt enclosed lamps (giving only about 250 candle-power) with the 300-watt, 600-candlepower nitrogen tungsten lamps, and to extend the system with 5,000 additional lights of this type. The largest saving in operating the nitrogen lamp under our local labor conditions lies in the trimming and patroling item. This saving is brought about by allowing 700 to 800 nitrogen lamps to be kept in repair, cleaned and patroled by a patrolman, who is allowed, besides his salary of $100 per month, $3.75 per day for the expense of an automobile supplied by himself to aid in his work; instead of a trimmer at $100 per month, trimming 330 arcs, and a patrolman at the same wage patroling 500 arcs, which averages approximately 200 arcs per man for trimming and patroling; making the relative saving 45 per cent for this item. Although the cost for four nitrogen tungsten renewals per year (which the manufacturer guarantees not to exceed) is nearly three times the annual cost for flame arc carbons, the relative saving in such items as the cost of power and fixed charges in the nitrogen installation more than offsets this high cost for lamp renewals. It is very probable that the life of these 20-ampere, 300-watt nitrogen lamps will, within a short time, materially exceed the present guaranteed 1,000-hour life, which would result in a still greater saving over that of the flaming arc. Electric Tungsten Residence Street Lighting Nearly 100 miles of our best residence streets which were formerly lighted with 50-candle-power gas lamps, have been relighted during the last two years with an underground, 4-ampere, 80-candle-power series lamp system, at a reduced annual expense per unit. A large saving was made in this installation by staggering the old gas lamp posts 150 feet apart on each side of the street and wiring them. Street Subway Lighting Over 400 street subways running under railway track have been lighted by the Electrical Department during the last eighteen months, at an installation cost aver aging $10 per 20-candlepower tungsten lamp. The standard spacing of these lamps averages one per 400 square feet over the roadway, and one per 2c0 square feet over the sidewalk area, which makes a well-lighted subway. The Commonwealth Edison Company supplies the energy, renews and maintains these lights under a five-year contract ordinance, and allows credit for all outage of the lamps, at $6 per lamp per year. Contract Lighting Rates The five-year contract ordinance which was passed by the City Council of Chicago on November 26, 1913, after a thorough investigation made by the city authorities of the Commonwealth Edison Company's books, gives a relatively lower schedule of rates for various kinds of electric service than any of the larger cities obtain by con RETAIL ELECTRIC LIGHTING RATES-CENTS PER KILOWATT HOUR. *Current furnished by water power. 10.0 $1.00, except Detroit. 6.7 $0.50 Baltimore. 7.3* Cleveland. $12 per year. In all of the above cities carbon incandescent lamps are renewed free, except Buffalo and San Francisco. (The above is based on 1 kilowatt load used 21⁄2 hours per day.) tract, except those being supplied by current generated by water power. The table on the preceding page gives the relative retail electric lighting rates of electric companies in the largest cities, based upon 22 hours' use per day of the maximum demand, which is the average for Chicago conditions: The two principal causes for these low rates in Chicago are the efficient generating units installed in the large central stations and the high load factor on the stations and system. The load factor has been materially increased by the sale of the power to the street surface and elevated railway lines. During the year 1913, 929,000,000 kilowatt hours were generated by the Commonwealth Edison Company. The total annual expense of the company for the year was $10,858,343.26, consisting of $7,957,299.99 cash costs, $1,547,127.44 depreciation and $1,353.915.83 taxes and municipal compensation. This shows a total cost of approximately 1.17 cents per kilowatt hour generated and distributed into the lines during the year. J Gas and Gasoline Lighting in Chicago by electric lamps each year, many gas lamps are replacing the uneconomical gasoline lamps in the outlying territory where the gas mains have been extended. The only expense to the city involved in extending gas services and erecting the gas posts is that for paving over the services. As this amounts to an average of less than $5 per lamp, a large saving is made by replacing the gasoline lamps with gas lamps where the gas mains are laid. Gasoline lamps were contracted for this year at $30.24 per lamp per year, while the annual cost for the gas lamps is $20.85, consisting of $9.09 for gas at 80 cents per 1,000 cubic feet and $11.76 for the maintenance and repairs. It will be noted from these figures that 43 per cent of the gas lighting cost is for gas alone, so that a 25 per cent reduction in our gas rate from 80 to 60 cents per 1,000 cubic feet would give about II per cent reduction on the total gas light cost; whereas, a 25 per cent reduction in the electrical current rate for arc lamps would mean less than 5 per cent reduction on the total arc lamp rate per year, as the electric energy cost is less than 19 per cent of the total cost. Street Development on a Terraced Hillside UST west of Twin Peaks, overlooking the beautiful Lake Merced and onward to the sea, is a picturesque residential section known as Ingleside Terraces. The distinctive feature of this bit of suburban planning is its yielding to the natural contour of the low hills that rise from the central plaza-yielding in such a way as to preserve all the beauty of glorious ocean views and none of the disadvantages of steep climbing. The tract-an abandoned race course HOW A PART OF THE FORMER RACE COURSE NOW APPEARS The sun dial is believed to be the largest in the world out with lawn and drives and flower beds, concrete seats and pedestals for jars of flowers, and, in the center, a great sun dial. Each level has an unobstructed view of the sea, and the highest are reached with ease by the winding, well-laid roads; in fact, an automobile can run at high speed on any grade there. Trellis lighting frames are placed about 100 feet apart on each side of the street, and are staggered. Each frame carries a 40watt lamp, hung over the center of the sidewalk and having above it a 20-inch corrugated white - enameled reflector. All the lights are connected with lead-covered cable, in wooden conduits. Better light is given with onehalf the current used in former systems. ONE OF THE ROSE COVERED ELECTROLIER TRELLIS FRAMES |