progress of work. The board is ruled in thirty-one numbered spaces, one for each day of the month. At the left-hand side are name plates in which cards can be inserted. The job number and the description are entered on the card, and colored map pins are inserted underneath the days at which the various stages of that job are to be completed. For instance, if a blue pin is inserted under the figure 2 and opposite job No. 46, it will indicate that the material for that piece of work should be on hand by the second of the month. Similarly, a green pin on the 12th would indicate that excavation should begin on that date, and so on. There is a movable slider which is advanced one day's space across the board each morning. This consists of a rod which runs in tracks at both the upper and the lower ends. This rod, therefore, cannot be lifted free from the board. As a consequence, when it is advanced, all the pins for that day must be moved from the space next to the right of the slider. In this way it automatically becomes impossible to overlook any of the pins, because they all have to be removed before the slider can be advanced. For work which is behind, the pin is moved ahead to a postponed completion date for that particular part of the job, and, correspondingly, other pins on the same job may have to be advanced.

With this device at hand, not even the smallest step in the progress of the work need be overlooked. Moreover, by glancing at the chart, the executive can tell exactly how any job stands and when its various parts will be completed. The grouping of too many pins of the same color under one

particular type of work has been laid out for that day, and will warn the superintendent in time, so that he will not overload the capacity of his apparatus or gangs.

Application of These Devices to the Work of Various City Departments Water-works superintendents can use to advantage a map showing the location of valves, hydrants and meters. On this can he indicated readily any changes which are made and also the occurrence of leaks requiring immediate and future attention. On new work, colored cords and pins can be used to show progress of excavation, pipelaying, and completed sections. The superintendent can also use the mechanical bar chart to keep an inventory of materials on hand at the city yards and to show the percentage of completion on any job. For this reason, the mechanical bar chart is ruled into one hundred spaces. Charts can be drawn in colored ink on engraved paper, showing daily consumption, also expenses.

Similarly, fire departments can use maps to show the location and character of each fire during the past year or a series of years, sticking in a new pin each time a fire occurs. By means of numbered pins the location of the various pieces of apparatus can be shown, also the location of hydrants and the routes of fire apparatus. In the same way, charts can be kept of the number of fires and of expenses incurred. Beads can be used to make a relief map of the buildings in the close fire district, each bead representing a story of the building, the color showing the type of construction.

The Park Commissioner can use a map

to show the location of various kinds of shrubbery in the parks, using a different colored pin to indicate each type of tree or bush. Several beads on a tall pin can also be used to indicate four facts about each tree or bush: the color of the top bead, for instance, represents the height, the color of the second bead the age, the third bead the kind of tree, and a fourth bead as to whether it has been transplanted or was grown on the spot.

The School Superintendent uses maps showing the homes of his pupils as a guide to the location of new school buildings, and the proper apportionment of these, also the location of special schools for backward children and for special work.

Superintendents of Health have used these devices now for many years, and literature is procurable explaining the use of them in city and state departments.*

Appropriation Chart

A unique chart which can be used to advantage by almost any department may be called an appropriation chart.† Nearly every department head is puzzled to know how he stands at any one time with regard to his appropriation, when it is subject to certain fixed expenses for salaries plus a fluctuating expense for repairs and equipment. This chart makes it easy for him to keep constantly before him the status of his appropriation.

Suppose, in the chart shown, the appropriation was $17,000. Suppose also that there are running expenses for salary and office costs amounting to $8,000 per year. A line is then drawn from the point marked o on January I to the $8,000 point on December 31. Suppose, for example, in the middle of February, a $2,000 purchase

* "Charts and Maps as Used by Health Officers," Gardner T. Swarts, Jr., C. E., American Journal of Public Health, Vol. VIII, Sept., p. 674.

This type of chart was first described by F. J. Shlink, Associate Physicist, U. S. Bureau of Standards. See Industrial Management, May, 1918.

APR 1 MAY I

JUNI

JUL I

AUG I

SEP 1

OCT I

ΙΛΟΝ

AN APPROPRIATION CHART

DECI

О

is made. In this case, the line is drawn vertically $2,000 high at February 15, and from the top of this another sloping line is drawn parallel to the first. This indicates that $10,000 of the appropriation has been used, and if office expenses and salaries remain the same, there will be but $7,000 available at the end of the year.

It so happens, however, that on April 1 a new employe is added. This employe receives $133 per month, or approximately $1,200 for the remaining nine months. A point on the December 31 line $1,200 above the $10,000 line is located, and a new line is drawn with a steeper slope, starting at April 1 and involving all the office expenses. and salaries, including the new employe's salary. About June 15, $800 more of material is purchased and another parallel line is drawn, indicating that approximately $12.000 has been spent and only $5,000 still remains to be utilized. Another purchase of $2,600 is made about August 15, but on October 1 an employe who receives $40 per month resigns, so that the slope

of the running expense line decreases. Further debts amounting to $2,800 are contracted during early November. During the first week of December, $400 worth of old equipment is sold, which is deducted. This scheme can be carried out indefinitely so as to show the actual condition of any appropriation at any given time.

The use of a simple diagram like this, involving only a minute's time whenever important purchases or changes in personnel are made, will save considerable embarrassment and will tell more at a glance than a set of books would.

Photographing Charts

For permanent record, it is convenient to blue-print charts, but pin maps and charts which are not on transparent paper have to be photographed each month or each year. These photographs are then filed away for reference. A great deal of care should be

used in planning maps or charts to be photographed, in order to see that the proper colors are used. For instance, blue reproduces as white, while red and yellow photograph black.

In large cities and in some city departments, the photostat machine is used for this purpose. In this machine, the photograph is made directly on sensitized paper, and not on a glass negative from which a print has to be made later. This process is considerably cheaper than photographing, and almost any document or map can be readily copied in this way.

Pin maps which are to be photographed should have the pins as close to the map as possible to avoid shadows and the danger of showing the pin out of position in the photograph. This is one of the reasons why the very soft mount mentioned in the early part of this article is recommended, as this type of mount makes it easy to push the pin away in up to its head.

$5.00.

This is the only elaborate treatise on graphics available. It contains 257 illustrations of charts and maps. Practically every type is shown. Chapters XI and XII deal with maps and map pins.

3. Graphic Charts for the Business Man.--Stephen Gilman. Pamphlet of 62 pages, 6 x 9 inches. 60 cents.

A very useful little pamphlet, taking up the elements of charting and showing over 50 practical illustrations of curves and charts in use. No information on map work in this pamphlet.

4. Charts and Maps as Used by Health Officers.-Gardner T. Swarts, Jr. American Journal of Public Health, September, 1918, p. 674. Also issued as a reprint, 25 cents.

5.

A thoro exposition of the possibilities and methods of applying graphics to public health work.

Millions for Paving Controlled by a Handful of Pins.-William H. Connell. Engineering Record, December 11, 1915, p. 714.

Graphic Methods

method of a combined map and visible card record.

6. Seattle Utilities Pay City for Subsurface Maps.-A. L. Valentine. Engineering Record, December 25, 1915, p. 792.

Besides explaining how this map work, costing $125,000, was paid for, Mr. Valentine shows two illustrations of sections of the map. Pins could have been used to good advantage to keep changes up to date in these maps.

7. Some Maintenance Expenses of a Small City. Charles J. Renner. THE AMERICAN CITY, May, 1914, p. 452.

This shows how to chart curves of city costs by months. Four actual curves are shown.

8. School Statistics and Publicity.-Carter Alexander. Book of 331 pages, 79 fig

ures, 5 x 71⁄2 inches.

A very comprehensive treatment of the possibilities of graphics as an aid to the school teacher and the superintendent. Shows good and bad methods and particularly treats of the advantages of presenting reports in graphic form. 9. Vital Statistics: An Introduction to the Science of Demography.-Prof. George Chandler Whipple. Book, soft leather covers; 517 pages, 44 x 7 inches, 148 tables, 63 figures.

A handbook for health officers and health statisticians, full of examples of graphic charts and explanations of how

I

N 1915, Le Roy, N. Y., a municipality with a population of 4,000 people, about 25 miles southwest of Rochester, installed a gravity water-supply system which has proved remarkably successful. Newark, N. Y., about 30 miles east of Rochester, has recently voted, by a majority of 3 to 1, an appropriation of $280,000 for a similar supply. This appropriation is noteworthy because it is made at a time when some nunicipalities are hesitating to push new construction work, in hope that prices will go down. The new supply of water is to be obtained by gravity by storing surface water in a large reservoir located on ordinary farm land and fed by streams draining land of a similar nature.

Strange as it may seem, while there are a great many instances all over the United States of cities that have obtained adequate supplies of soft water by the construction of storage reservoirs, there are, nevertheless, many municipalities that have sought to supplement their inadequate supplies of hard water by pumping either from a lake or from wells. The writer knows of a municipality that has spent $350,000 to pump against a head of 600 feet, altho an equally good supply could have been obtained by gravity at slightly less expense. Once constructed, the gravity system re

moves from the minds of the citizens and the municipal officials practically all the worries caused by the emergencies of pumping system operation, such as rising prices of coal and shortage of supply, as well as the troubles which are experienced with most well systems.

The Le Roy Reservoir

The construction of the gravity system at Le Roy, N. Y., and the proposed construction of a similar system for Newark, N. Y., well illustrate the advantages of the gravity system.

The accompanying photograph shows the site of the lower dam at Le Roy from the up-stream side before the dam was constructed. The heavy line represents the crest of the dam. The reservoir basin was ordinary farm land, with a drainage area of about 1.7 square miles, also of ordinary farm land, with fourteen or fifteen dwellings having farmhouse privies on the watershed. The stream which flows into the reservoir dries up during the summer, and sometimes for three or four months during the year no water flows into the reservoir. It is designed with a sufficient capacity to furnish three times Le Roy's daily consumption for an entire year even if no water whatsoever enters the reservoir for six

months.

Since it was constructed it has been necessary to draw down the reservoir only 21⁄2 feet, and it is possible to draw as much as 14 feet to the level of the intake. This illustrates the value of careful study in selecting the location and determining the size of a storage reservoir, as during the last seven years meteorological reports show that the rainfall has been below the average.

The Le Roy Filtration Plant Directly in front of the dam of the Le Roy reservoir is a 1,000,000-gallon rapid sand filtration plant. Because of the large storage reservoir, which permits considerable settling of the water before it reaches the filtration plant, it is necessary to use but a very small quantity of alum.

The entire expense of operating the filter plant and taking care of the reservoir during the last fiscal year was about $1,390. Of this amount, $470 was for the alum, $212 for gasoline to operate the engine furnishing the water to wash the filters and also to operate the air blowers, $48 for coal to heat the plant, and $720 for the man who operates the plant. The filter plant is located at the reservoir, and the man in charge of it is allowed to work some of the extra land owned by the city, in order to increase his salary. It takes about an hour and a half daily to care for the plant, and the rest of the time the man is permitted to spend outside. Alum prices in the past year have been abnormally high on account of the

war-about $75 a ton; approximately seven tons were used during the year..

The water consumption of Le Roy is about 300,000 gallons daily. The filter plant is not in any sense an elaborate proposition. It is an inexpensive plant used solely as a precautionary measure to remove contamination and the turbidity which results from heavy rains or from the winds stirring up the surface of the reservoir.

Chlorination of Supplies

Sterilization by chlorine is used at Le Roy, and repeated bacteriological examination of the water shows that B. coli is very seldom present, as the period of storage in the large reservoir renders the water practically "epidemiologically sterile" before reaching the filter plant. Newark, N. Y., already owns a chlorinator which is being used in connection with the present pumping plant, and chlorine will be used in the new supply at least during certain parts of the year and whenever the least trace of contamination is found.

When a chlorinator is used in connection with a gravity supply, it is of considerable importance to have an automatic apparatus controlled by a Venturi tube so that the amount of chlorine varies in proportion to the volume of water, otherwise there is apt to be a pronounced taste of chlorine at night or on Sundays, when very little water is used. This, however, may be taken care of by providing a full-time operator who observes and records the amount of chlorine