Page:The American Cyclopædia (1879) Volume VI.djvu/65

DEVIL'S WALL DEVONIAN 57 matt, by which the road from Switzerland to Italy by the pass of St. Gothard crosses the I Reuss. The original bridge was built by Abbot Gerold of Einsiedeln in 1118, and was partly destroyed by the French, Aug. 14, 1799. It was afterward restored, but is no longer in ac- tual use. It spans the river at a height of about 80 ft., without a parapet. The bridge now in use, completed in 1830, is about 20 ft. higher than the old one, or 100 ft. above the river, with high parapets ; its arch has a span of 25 ft. Near the bridge is a tunnel 180 ft. long, through which the road passes, called the Urnerloch, or hole of Uri. DEVIL'S WALL, a name given during the middle ages to the remains of some Roman fortifications designed to protect the settle- ments on the Rhine and the Danube against the inroads of the German tribes. These de- fences originally consisted of a row of pali- sades, in front of which extended a deep ditch. The emperor Probus strengthened them by the erection of a wall about 300 m. long, passing over rivers and mountains, and through valleys, and protected by towers placed at intervals. Portions of this wall are still distinguishable between Abensberg in Ba- varia and Cologne on the Rhine. In some places the ruins are overgrown with oaks, in others they form elevated roads or pathways through dense forests. DEVISE, the disposition of lands to take effect after the death of the devisor. It is a term of Norman origin, and signified at first any division of lands, marque cle division ou partage de terres, from the Latin dimdo. The instrument by which lands are devised is called a will. The disposition of personal estate to take effect after the death of the person making it is in legal language a tes- tament; but the common appellation, where both real and personal estate are included, is last will and testament. The Roman testa- Amentum applied equally to the disposition of real or personal estate, and the same rules were observed in either case. But the mode of executing a will has been always more formal in England than was required for the validity of a testament. (See WILL.) DEVIZES, a parliamentary borough and market town of Wiltshire, England, on the Great Western railway and on the Kennet canal, 82 m. S. W. of London ; pop. in 1871, 6,840. It contains two handsome parish churches, besides other places of worship, and a fine town hall. Its manufactures are chiefly silk, crape, snuff, and malt. The grain market held here every Thursday has been famous ever since the time of Henry VIII., and is still the largest in the west of England. The town is supposed to owe its origin to a strong castle built here in the reign of Henry I. by Roger, bishop of Salisbury, and dismantled toward the close of the reign of Edward III. DEVONIAN, the name of one of the geologic ages, the age of fishes, and the second of the three ancient or palaeozoic divisions of time. It followed the Silurian, or age of mollusks, which till recently was thought to contain the earliest vestiges of organic life, and preceded the carboniferous. These three ages, constitu- ting the paleozoic era, were followed by the age of reptiles, which constitutes the mesozoic era. The Devonian age, or Devonian formation, as the rocks are called, was named from Devon- shire in England by Sir R. Murchison and Prof. Sedgwick, who about the year 1837 distinguish- ed its strata from those of the Silurian below and the carboniferous above. The transition of the Silurian to the Devonian formation is gradual and easy, and sometimes rather diffi- cult to determine ; so much so that differences of opinion exist in regard to some of the strata in certain localities ; but a broad distinction in the two ages is marked by the forms of the development of life. The periods and epochs into which the Devonian age is divided, ac- cording to the system of the New York state geologists, are as follows : DEVONIAN AGE. 5. Catskill period 4. Chemung period 8. Hamilton period 2. Corniferous period.. 1. Oriskany period Catskill red sandstone. 2. Chemung epoch. 1. Portage epoch. 3. Genesee epoch. 2. Hamilton epoch. 1. Marcellus epoch. 3. Upper Helderberg epoch. 2. Schoharie epoch. 1. Cauda galli epoch. Oriskany red sandstone. The first and second periods are often called the lower Devonian, and those above, the upper Devonian. The corniferous was the great lime- stone period of America. Above it shales and sandstones predominate, the limestone beds being subordinate. The Oriskany formation, named from Oriskany, Oneida co., N. Y., is about 30 ft. thick at that place, composed mainly of rough sandstones. Along the Alle- ghanies it extends through Pennsylvania, Mary- land, and Virginia, and in these states often reaches a thickness of several hundred feet. No land plants have been found among its fos- sils, and the mass of evidence points to the non-existence of land vegetation during the Oriskany period. The most common species of animals are the spirifer arenosus and Bens- selaeria ovoides, their large fossil shells being often crowded together, and composing a good share of the rock. The cauda galli epoch of the corniferous period is named from the feathery forms of a fossil, supposed to be the impres- sions of a seaweed. The rock is principally argillaceous sandstone, and in the Helderberg mountains, near Albany, N. Y., is from 50 to 60 ft. thick. The rocks of the Schoharie epoch are principally fine-grained, calcareous sand- stones, full of fossils. In New York the beds are all in the eastern part of the state. The rocks of the upper Helderberg epoch are lime- stones, and are widely distributed over the interior continental basin from New York to beyond the Mississippi. In New York they