A. It illustrates an attempt to do something that this gentleman here was asking about. The idea is to make the initial burning surface very large, the object being to reach the maximum pressure as soon as possible. This is followed by a sudden drop in the burning surface just before the maximum pressure is reached; and from that time on the grain will burn with a gradually increasing surface.

CARL HERING: What is the effective range of the 16 inch gun?

A. Mounted on a carriage permitting an elevation of 45 degrees, it is calculated that it would give a range of between 20 and 21 miles.

MR. HERING: Is there any object in building a gun to shoot as far as that?

A. That is simply an illustration of the power we are trying to obtain.
CHAIRMAN: Over a shorter range there is a more direct trajectory?

A. The larger and heavier the projectile, the less the effect of air resistance is in proportion to any given velocity and the greater the range.

A MEMBER: I would like to ask what the practical elevation is?

A. For heavy guns the elevation is 15 to 20 degrees, for howitzers, or mortars up to 70 degrees, and for balloon guns up to 90 degrees.

MR. CASGARTEN: I think mention was made of using smokeless powder and a silencer; I think that is not quite correct. According to my experience, the noise of shooting combines two noises, one produced by the gases, and the other produced by the bullet as it flies through the air, and neither can be avoided by the silencer; is that not correct?

A. Quite correct.

MR. HERING: You spoke of firing at an angle of 90 degrees; how do you protect the gunners?

A. No projectile comes down as it goes up; that is, not at the same angle. The carriage permits firing at an angle of 90 degrees, but it is not likely that the gun would be fired at that angle.

PAPER NO. 1113.

THE QUEEN LANE FILTRATION PLANT.

S. M. SWAAB.

(Active Member.)

Read June 1, 1912.

INTRODUCTION.

THE subject of the water supply of the city of Philadelphia has received considerable attention from The Engineers' Club, and in our Proceedings are several papers descriptive of the works. It is not my intention, other than in a general way, to speak of the Water Supply per se; but rather to describe in detail, historically and otherwise, the construction of the last unit of the Filtration System, begun in the year 1901, and prosecuted during about ten years of the period intervening between that date and the present.

This paper contains a historical sketch of the Queen Lane Filter Project, as well as a description of the construction and method of operation of the Queen Lane Filter Plant of the Philadelphia Water Supply, and also a brief outline of the process of the purification of water by slow sand filtration and of the evolution of that process.

HISTORICAL.

Benjamin Franklin it was, I believe, who first publicly called the attention of the citizens of Philadelphia to the very important subject of obtaining water for the city from some other source than the wells then universally used, urging that the affiictions from the ravages of contagious disease rendered it necessary that a more copious supply of water should be procured to insure the health, comfort and preservation of the citizens.

This was about the year 1793 or 1794, just after the city had been visited by the yellow fever; and in Franklin's will, dated June 23d, 1789, is the following clause: "And having considered that the covering of the ground plot of the city with buildings and pavements, which carry off most of the rain, and prevent its soaking into the earth, and

renewing and purifying the springs, whence the water of the wells must gradually grow worse, and in time be unfit for use, as I find has happened in all old cities, I recommend that, at the end of the first hundred years, if not done before, the Corporation of the City employ a part of the 100,000 pounds in bringing by pipes, the water of the Wissahickon Creek into the town, so as to supply the inhabitants, which I apprehend may be done without great difficulty, the level of that Creek being above that of the city, and may be made higher by a dam. I also recommend making the Schuylkill completely navigable."

Less than one hundred years after the date of Franklin's will a commission reported on a scheme for procuring water for the city from the upper Delaware. The recommendations of this report were never acted on and about one hundred and ten years after the date of his will, the commission appointed by Mayor Ashbridge recommended the filtering of the water of the Delaware and Schuylkill Rivers within the city limits, which, with the completion of the work described in this paper, has been entirely accomplished with all of the beneficent results which were predicted.

The site now occupied by the Queen Lane Filter Plant and Reservoir was occupied in Revolutionary times by Washington as a military camp. A granite obelisk at the northerly corner of the plant has the following inscription:

THE MAIN CONTINENTAL ARMY COMMANDED BY
GEN. GEORGE WASHINGTON ENCAMPED ON THIS
AND ADJACENT GROUND FROM AUG. 1 TO AUG. 8
AND FROM SEP. 12 TO SEP. 14, 1777, BEFORE
AND IMMEDIATELY AFTER THE BATTLE OF
BRANDYWINE.
ERECTED IN 1895

BY THE PENNA. SOCIETY OF SONS OF THE
REVOLUTION TO PERPETUATE THE MEMORY OF
THE ENCAMPMENT.

HISTORY OF THE QUEEN LANE FILTER PROJECT.

On September 1st, 1896, Mr. Allen Hazen, in a report to the Woman's Health Protective Association, entitled, "A Practical Plan for Sand Filtration in Philadelphia," proposed as part of a comprehensive scheme a filter plant of an average daily capacity of 26,000,000 gallons and of a maximum of 39,000,000 gallon occupying 40 acres west of Wissahickon Avenue bet

south of School Lane and Queen Street, immedi:

Queen Lane Reservoir. The land alone was estimated to cost $200,000.

Mr. John C. Trautwine, Jr., Chief of the Bureau of Water, on September 9th, 1908, submitted to Mr. Thomas M. Thompson,

Director of the Department of Public Works of Philadelphia, a report on "Filtration, with Plans and Estimates of Costs, etc.," in which he proposed a rapid or mechanical filter plant located on private property north of Thirty-first and Queen Streets for the Queen Lane

section. The capacity of the plant, as proposed, was 30,000,000 gallons daily.

In a paper by Mr. John W. Ledoux, of January, 1899, "Concerning the Water Supply Problem of Philadelphia," he suggests as part of a scheme of slow sand filtration the use of the north compartment of the Queen Lane Reservoir, in which he proposed to build 19 acres of filter beds; and he also suggests the construction of a masonry dividing wall in the south compartment of the reservoir, the westerly part of which was to be retained in service as a sedimentation basin, and the easterly section as a filtered water basin.

On September 15th, 1899, a report was submitted to Mayor Samuel H. Ashbridge by Messrs. Rudolph Hering, Joseph M. Wilson and Samuel M. Gray, a commission which he had previously appointed in accordance with a resolution of City Councils of April 20th, 1899, for the purpose of investigating and reporting on a general scheme for the "Extension and Improvement of the Water Supply." The recommendations of this commission, as far as Queen Lane was concerned, were to purchase for the site of the plant the Smith property on the north side of Queen Street west of Wissahickon Avenue, on which they proposed to build 27 filters, each of an area of about three-fourths of an acre, and to subdivide the South Basin of the reservoir into two compartments, the easterly one of which was to be used as a filtered water basin, exactly as in the scheme of Mr. John W. Ledoux above outlined. The plant was to have a capacity of 58,000,000 gallons daily, and in the estimate there is set aside the sum of $310,000 for the purchase of the site. Subsequent to the publication of the commission's report, and after the actual construction of the works now approaching completion was started, many parts of the general scheme were recast, many details changed, the entire scheme amended by the introduction of preliminary treatment of the water, and the distribution districts in many cases enlarged or altered. One of the changes proposed by Mr. John W. Hill, then Chief Engineer of the Bureau of Filtration, was to abandon the project of filtration at the Queen Lane site, and to build certain filters at the Torresdale Filter Plant, which were to be known as the Queen Lane Contingent. The water treated in these filters was to be pumped through the Queen Lane distribution districts from the Lardner's Point pumping station by the pumps which are at present in the Queen Lane pumping station on the Schuylkill, which station it was proposed to abandon. The pumps were to have been rebuilt