The only attempt to measure with accuracy the rate of the accumulation of stalagmite in caverns, in this country, is that made by Mr. James Farrer in the Ingleborough Cave, in the years 1839 and 1845, and published by Prof. Phillips in the “Rivers, Mountains, and Sea Coast of Yorkshire” (second edition, 1855, pp. 34-35). The stalagmite of which the measurements were taken is that termed, from its shape, the Jockey Cap. It rises from a crystalline pavement to a height of about two and a half feet, and is the result of a deposit of carbonate of lime, brought down by a line of drops that fall into a basin at its top, and flow over the general surface. On March 13th, 1873, in company with Mr. John Birkbeck and Mr. Walker, I was enabled by the kindness of Mr. Farrer to take a set of measurements, to be recorded for use in after years. For the sake of insuring accuracy in future observations, three holes were bored at the base of the stalagmite, and three gauges of brass wire, gilt, inserted; gauge No. 1 in the following table being that on the S.S.E., No. 2 on N.N.E., No. 3 on the West side. The curvilinear dimensions were taken with fine iron wire, or with a steel measure; and the circumferential around the base along a line marked by the three gauges. The measurements 2, 3, and 4 of the table were taken on the 15th of March, by Mr. Walker, and their accuracy may be tested by the fact that they coincide exactly with No. 1, which I took two days before. The lengths of wire, properly labelled, are deposited in the Manchester Museum, the Owens College, for future observers. In the following table I have given my own measurements and compared them with those taken by Mr. Farrer. TABLE OF MEASUREMENTS.