492 HARTSVILLE HARTZ 1694 Hartsoeker published there an Essai de dioptrique, followed in 1696 by Principe* de physique. He afterward returned to Holland, and while there was introduced to the czar Peter, who endeavored without success to in- duce him to settle in St. Petersburg. After filling for several years the professorship of mathematics in Diis- seldorf, he retired to Utrecht. One of his last works was Recueil de plusieurs pieces de physique, in which the system of Newton was assailed with more vio- lence than force. Pre- vious to this he pub- lished his lectures un- der the title of Conjec- tures physiques (Am- sterdam, 1706-'8), and a number of other works, many of a con- troversial nature. HARTSVILLE, a town of Bartholomew co., Indiana, about 40 m. S. S. E. of Indianapolis ; pop. in 1870, 433. It is the seat of Hartsville university, established in 1851 under the au- spices of the United Brethren, which in 1872 had 14 professors and instructors and 117 students, mostly in the preparatory depart- ment, of whom 38 were females. The theologi- cal school connected with the university had one professor and 11 students. HARTWICK, a town of Otsego co., New York, situated on the Cooperstown and Susquehanna Valley railroad, 4 m. S. of Cooperstown and Otsego lake, and about 60 m. W. of Albany ; pop. in 1870, 2,339. The surface is a hilly up- land, the highest summits being from 200 to 350 feet above the valleys. The E. part is drained by the Susquehanna, and the W. part by Otego creek. The town contains four post offices, viz. : Hartwick, Hartwick Semi- nary, South Hartwick, and Toddsville. In the village of Hartwick Seminary is Hartwick theological and classical seminary, incorpora- ted Aug. 13, 1816, and endowed by John 0. Hartwick, from whom it received its name. The building has recently been remodelled, and is now one of the finest seminary buildings in the state. Hartwick seminary is connected with the Lutheran church, and in 1873-'4 had 5 instructors and 85 students, of whom 60 were males and 25 females, and 7 were in the theo- logical department. There are 3,000 volumes in the library. HARTZ (Ger. ITarz, or Earzgebirge), the most northwestern mountain range in Germany, between lat. 51 30' and 52 N., and Ion. 10 10' and 11 30' E. It separates the waters of the Weser from those of the Elbe. This range is divided into two parts, Upper and' Lower The Brocken. Hartz, lying W. and E. of the Brocken. Their principal axis, which extends in a direction about W. N. W., E. S. E., is not far from 60 m. in length. The width of this main chain, as from Wernigerode to Ilfeld, is about 18 m. The highest summit is the Brocken, a mountain of feldspathic granite, which by its easy decom- position has caused the mountain to assume a rounded graceful form. It rises to the height of 3,737 ft., and overlooks all the surrounding country. The Rosstrappe stands near by in the same group, and is of somewhat inferior eleva- tion to the Brocken, from which it is separated by formations of argillaceous slates and the lower limestones. It is composed of granite in which quartz predominates, giving to the rock a more indestructible character and to the mountain a more rugged aspect than that of the Brockm. The Rammelsberg is a mountain of argillaceous slate and the older sandstones, reaching the height of about 1 ,200 ft. above the plain near the town of Goslar. The district comprising these mountains is principally made up of granitic rocks, which form the highest summits, and of gneiss, argillaceous slates, and metamorphic
