openings, 2 x 24 inches at the periphery (see figure). The action of the pump was to draw the water through a short suction pipe, 7 inches in diameter, into the central chamber, and project it from the outward end of the curved arms into the shell of the pump, and thence through a 6-inch discharge pipe to the canvas hose.

The engine and pump, with band-wheel, belt, etc., weighed 6000 pounds, and was placed upon a raft so as to follow the water as it sank in the pit.

The following table is a résumé of data collected and averaged. It exhibits the operation of the pump under various circumstances.

NOTE -The velocity of the periphery of the pump piston or wheel at 400 revolutions is 2500 feet per minute, at 575 revolutions 3600 feet per minute, and at 730 revolutions 4600 feet per minute.

The figures in column A show the lift from the surface of the water to the top of discharge hose.

Columns B, C, D, and F are averaged.

Column E is the speed which the pump should attain calculated upon the velocity of falling bodies; that is, the velocity of the periphery of the rotary piston should be equivalent to that required by a body falling 1 times the height of lift, the allowance of fifty per cent. being for friction, etc.

Column G shows the duty in million pounds raised one foot high by the consumption of 100 lbs. of anthracite pea coal, without any allowances, the quantity of coal consumed, water pumped, and height of lift being only considered.

The decrease in the coal consumed at 15 and 25 feet lift was owing to the protection of the steam pipe. As there was considerable condensation in the long steam connection, and leakage in the canvas hose, a fair allowance would place the average duty at, say, 15 million foot pounds, and the maximum duty between 20 and 25 millions.

By comparing columns D, E, and G it will be noticed that as the actual speed varied from the theoretical speed the duty increased. This may partially be explained by assuming that the allowance for fifty per cent., as above, is excessive, but it is undoubtedly owing to the fact that the leakage at low velocities is comparatively greater than in high velocities, that is, the leakage was not in proportion to the height lifted. Had it been possible to attain greater speed the duty would have undoubtedly been increased.

By the time bottom was reached the canvas hose gave so much trouble that it was abandoned and 8-inch wrought iron tubing substituted. The above memoranda were all taken, however, while the canvas hose was in use.

152 South Fourth Street, Philadelphia.

THE FIRE-CLAYS AND ASSOCIATED PLASTIC CLAYS, KAOLINS, FELDSPARS, AND FIRE-SANDS OF NEW JERSEY.

THEIR GEOGRAPHICAL DISTRIBUTION AND GEOLOGICAL OCCURRENCE.

From the work of the Geological Survey of New Jersey.

BY PROFESSOR J. C. SMOCK, ASSISTANT GEOLOGIST, NEW BRUNSWICK, N. J.

(Read at the Philadelphia Meeting, February, 1878.)

THE fire-clays of New Jersey belong in two geological ages, the cretaceous and quaternary, or post-tertiary. Three very small deposits of plastic clays have been discovered within the limits of the Archæan rocks. These are not refractory and of little importance, excepting in a geological consideration. They have resulted from a decomposition of the feldspars of the rock in situ, and they have been classified as inferior kaolins.

VOL. VI.—12

All of the fire-clays, fire-sands, and the so-called kaolins* and feldspars are sedimentary formations. They have come from the decomposition of crystalline, feldspathic rocks. The source of this vast amount of material was probably a continental area, or belt of land, southeast of our present Atlantic coast-line. The isolated, granitic outcrops at Jersey City and on Staten Island appear to belong to a submerged and covered Archæan formation, which was once a continuous belt from New York to Trenton, and thence southwestward.

The several outcrops and localities, where these strata of fire-clays and other refractory materials occur, are grouped geographically in three districts of the State. The most important of these is in Middlesex County, east of New Brunswick, and extending to the Staten Island Sound and Raritan Bay. Its northern limit is a line parallel to the Pennsylvania Railroad, from New Brunswick to Rahway, and about two miles south of it. The Chesquake Creek forms the south boundary. This district has an area of sixty-eight square miles. It has been very carefully surveyed and represented upon one of the maps† of the geological survey, on a scale of th, or three inches to a mile. The well-known Woodbridge and Amboy clays, kaolins, and fire-sands come from this district.

ΣΤ

The second district is geologically one with that above described. It is the extension of the latter across the State and along the Delaware River, from Trenton and Bordentown, southwest to Salem County, where it passes out of the State, and thence crosses the river and appears in Delaware. The Trenton, Florence, Pensauken Creek clays, etc., are in it. The third district, or (more properly speaking) group, includes all the more recent clay deposits of that part of the State which is south and southeast of the green-sand marl belt. The clays at Conrad, in Gloucester County, and those of Wheatland and the Union Clay Works in Ocean County, are the principal localities. As above stated, the first, or Middlesex County clay district, is the most important, and it produces an aggregate many times larger than the sum total of all the rest of the State, as well as materials of superior quality and of more value. This district is bounded on the northwest by the Triassic shales and sandstones, and the beds of clay overlie these. The glauconitic, clayey marls bound this district

* These terms have been greatly perverted by local usage in New Jersey. By kaolin is understood a micaceous sand; by feldspar, a mixture of round grains of quartz, and sand, and fire-clay.

† See report on the clays of Woodbridge, etc., Trenton, 1878.

on the southeast, and the strata of marl are seen upon the top of the clay series. Between these geological limits the following beds are recognized as distinct and marked by characteristic features. They are, beginning at the top:

Dark-colored clay (with beds of lignite),

Sandy clay with sand in alternate layers,

50 feet.

40

The dip of this clay formation corresponds in direction to that of the green-sand marl beds on the southeast. An interesting feature of this dip is the diminishing rate in going from the older to the newer, or from the northwest to the southeast. Thus, in the Raritan clay bed it is 60 feet per mile; in the Woodbridge and South Amboy fire-clay beds, 51-48 feet; and in the Stoneware clay bed, only 30 feet, or the same as that of the marl beds above it. As is well known, the Triassic shales dip towards the northwest, and at much higher angle than that of these clay beds. The latter are seen lying unconformably upon the former.

Nearly all of these strata, or members of this formation, contain materials of more or less value in the arts, and especially so in the manufacture of fire-bricks and furnace-linings of all kinds, gashouse retorts, sewer and drain pipes, various ceramic products, and pottery in general. While there is much variation in the character of the materials found in any one of these, there are general features which are characteristic, and enable the miner to recognize it, and then determine its prospective value.

The early recognition of these distinguishing features is very important to the explorer and miner. Some of these, with descriptions of localities, are here given, following the order of the geo

logical column, or series, as above, but beginning with the lowest member, the

Raritan Potter's Clay Bed.-This bed reposes directly upon the red shale and sandstone of the Triassic age. It has been opened at comparatively few points, and at none of them has there been much work done in digging or mining the clay. Its more important localities are the pits in the vicinity of Piscataway and Bonhamtown. The clay of this bed lacks that degree of homogeneity so characteristic of the higher fire-clay beds. It is very frequently laminated in structure, and appears to be a mixture of materials from different sources and of somewhat unlike characters. Much of it is, however, very white, almost free from gritty particles, and resembles some of the finest of the Woodbridge clays. But it does not stand in the fire, and cannot be considered a fire-clay, although there are thin sections of it quite refractory. Its composition is shown in the following analyses :

Separated from this clay by a thin bed of lignitic, sandy clay, there follows the Raritan fire-clay bed. This is marked by a drab color, and more sandy texture. It has been recognized by its elevation and these marks in Dixon's pits at Woodbridge, and in several small pits near Bonhamtown. The clay of this bed is more dense, and corresponds to some of the foreign glass-pot clays. It has been tried for crucibles for steelmakers and for glass pots, but not so fully as to establish a character for it. It is a good fire-clay for brickmaking. Analysis shows its composition to be as follows: