D Greywacke formation, up to the limestone. 1 Compact greywacke Manadon-hill, Swilly &c 2 Granular greywacke Mount Tamar, 3 Greywacke slate; 4 Siliceous Slate 5 Rude porphyry 6 Micaceous greywacke? E Dip not usually distinct; where visible, south-Reposing upon slate-Forms a range of high ground, running north and south from Knackersknowle to Townsend-hill; and from Swilly, west, many miles eastward-Highly fertile and well wooded-Not metalliferous. Dip south; reposing on D 2.Forms Lipson-hill, Northill, and all that line east and west. Rather retentive of damp; but sufficiently fertile. Dip south; reposing on greywacke slate; forming Warleigh-tor. > Detached rock, near St. Budeaux. Dip south east. A small bed, a little south of the above: dip south-Soil fertile. Rocks of the shore. 1 Limestone, with corallite &c. 2 Ditto with univalve shells 3 Ditto with bivalves 4 Greywacke Drake's Island Dip not quite uniform; generally south-Reposes on greywacke slate, with which it alternates, north, as it does south, with red sandstone, which lies above it. Forms a sea boundary of low hill covered with a fertile soil; but thin and subject to parch in Not metalliferous. Dip quite irregular, and apparently disturbed: yielding to the weather. summer 5 Greywacke Boveysand Bay 6 Ditto passing into red sandstone. 7 Red sandstone, compact, Mount Edgcumbe and Staddon-heights 8 Ditto porous Cawsand Bay 9 Greywacke slate Jenny Cliff, Mewstone, Penlee and Rame 10 Rock quartz; Andurn point to the Shagstone F 1 Gneiss Dip uncertain; appearing thrust up from beneath; and to have heaved the red sandstone strata saddlewise. Little exposed; dip variable and irregular: apparently disturbed by heaving from beneath. Dip irregular, often vertical in Cawsand-bay, where it is interlined with white sandstone, looking like mortar. The course of the bed also irregular; but having a prevailing tendency south east-Slate is generally intermixed with it. Dip, at Jenny Cliff and Mewstone south west-at Penlee, it is vertical that at Jenny Cliff and the Mewstone is intermixed with sandstone. A broad vein of compact quartz, running through the red sandstone and having resisted the encroachments of the sea on its matrix. Rocks of the Eddystone. House rock 2 Ditto, passing into granite 3 Granite A single rock, probably 200 feet square; I believe the only gneiss in England. Dip, south west, Dip south west. The rocks nearest the gneiss contain the largest proportion of felspar; and have the most laminar texture. II. EXPERIMENTAL INQUIRIES CONCERNING THE LAWS OF ELECTRICAL ACCUMULATIONS, BY MR. W. S. HARRIS, MEMBER OF THE PLYMOUTH INSTITUTION. 1. THE peculiar arrangement of an insulated and uninsulated conductor exemplified in the construction of the Leyden Jar, appears calculated to develope, in a satisfactory way, many important properties of electrical action; it has consequently undergone, at various periods, so much investigation, that it would seem difficult to give any new interest to researches in this interesting department of science; but after a long series of observation and experiment, carefully compared with the present advanced state of our information, I am led to believe, that the following paper, will be found to contain some new and important facts, which appear hitherto to have escaped observation; and, I may therefore hope, that it will not be deemed unworthy of the Society's attention. It may not be improper or uninteresting, before I proceed more immediately to the experimental inquiries, which are the subject of this paper, to give a sort of general account of the |