just across the line in Middlesex county. It varies from 7 to 14 feet in thickness, is variously colored, and is overlain by several feet of sand. At present it is dug by the Excelsior Terra Cotta Company for use in their factory at Rocky Hill.

Clay-working Industry.-Common brick are made at the three yards as already mentioned, and terra cotta is manufactured at Rocky Hill by the Excelsior Terra Cotta Company, but the clay is obtained chiefly from Middlesex county, although some of it is dug at pits a mile or two northeast of the works.

Cook & Smock, Report upon the Clays of New Jersey, 1878, p. 232.

SUSSEX COUNTY.

The clays of Sussex county so far as known are exclusively glacial or alluvial in origin, and are not extensively worked.

Newton.-A black clay containing much organic matter is dug for common brick at Newton (Loc. 285). The clay is about 8 feet in thickness and is found at the margin of the large tract of swamp land lying just north of the city. It is highly probable that clay underlies the whole of this area, although somewhat buried by swamp muck towards the center. The tract was probably a shallow lake at the close of the Glacial period. The presence of the organic matter indicates that swamp conditions. prevailed to a greater or less extent when the clay was formed. Branchville.-A sandy glacial clay of the following composition is found near Branchville:

Ogdensburg. Highly calcareous clays are found on the property of A. D. Tallman, at Ogdensburg (Loc. 292), but so far as known they are not worked.

Clays are also known to underlie the drowned lands along the Wallkill river, but they are not available commercially.

Sussex (Deckertown).—Clay was formerly dug for brick along Clove brook not far from Fuller's mill.

These probably do not exhaust the localities in this county at which shallow clay deposits occur, but they include the more important ones which have been brought to the notice of the Survey.

UNION COUNTY.

Murray Hill.-A red-burning clay occurs at Murray Hill, on the property of H. Wilcox (Loc. 290). It is fairly plastic, working up with 30.8 per cent. water to a mass whose air shrinkage is 8 per cent. The tensile strength was 134 pounds per square inch. The clay had a high fire shrinkage at cone 05 of 11 per cent. and an absorption of 3.12 per cent. It burned red and steel-hard at this cone. At cone I it began to fuse, so that it is a very easily fusible material, but burns to a hard red brick at a rather low temperature.

Elizabethport.-Red clay for common brick,1 6 to 10 feet deep, has been worked at Elizabethport for a number of years, at Jacob Hammer's plant, located on south Front street and Bayway.

Berkeley Heights.—A bed of black clay, 30 feet deep and covered by 1 to 2 feet of soil, has been worked at Berkeley Heights, under lease by Kresner & Holland, for common-brick manufacture.2 The clay is said to be free from grit and very plastic.

Linden.-A very plastic surface clay near Linden is drawn on for supplying several earthenware potters in neighboring towns. It is red burning.

Netherwood.-A very tough, stiff-working clay, requiring the admixture of large quantities of loam, has been worked at Netherwood for brick, but none were being made when the canvass for this report was undertaken.

1N. J. Geol. Surv., 1898, p. 205.

2 Ibid.