616 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



tatinc disc of metal haviuo; slits in its circumference so as to admit 

 and intercept the solar beam, is placed in a dark chamber, between 

 it and the observer is a ground glass screen to receive the beam. 

 When the disk rotates slowly the separate appearances of the 

 beam are distinguished. At higher velocities the image of white 

 light is tinged with blue, green, rose, white, green, blue, in this 

 order. After the second blue, the image is white at all higher 

 velocities of rotation. 



Remains of a Gigantic DinosaueI. 



Professor E. D. Cope exhibited at the Academy of Natural 

 Sciences, Philadelphia, the remains of a gigantic extinct Dinosaur, 

 from the cretaceous green sand of New Jersey. The bones were 

 portions of the under jaw, with teeth, portions of the scalpular 

 arch, including supposed clavicles, two humeri, left femur, right 

 tibia and fibula, w^ith numerous phalanges, lumber, sacral and 

 caudal vertebrae, and numerous other elements in a fragmentary 

 condition. In size this creature equaled the Megalosaurus (70 

 feet in length), and must have been one of the most formidable of 

 the rapacious terrestrial vertebrates. The remains were found by 

 the workmen under J. C. Voorhees, superintendent of the West 

 Jersey Marl Company, about two miles south of Barnesboro', just 

 under the stratum of green sand (now used as a manure), and 

 about twenty feet from the surface. 



Mount Hood. 



This mountain, the highest of the Cascade range, situate about 

 seventy miles east of Oregon City, was visited in August last by 

 a party of six gentlemen, who ascended to the summit. One of 

 them, Professor Alphonso Wood, gave a detailed account of the 

 trip before the California Academy of Natural Sciences. He 

 measured various altitudes, by •observing the boiling point of 

 water, as follows : Summit of the Cascade range and foot of 

 Mount Hood proper, 4,400 feet ; the limit of forest trees, 9,000 

 feet ; highest limit of vegetation, 11,000 feet ; summit of moun- 

 tain, 17,600 feet. He describes a crater of great extent, the west 

 side of which is still an open abyss, whence issues constantly 

 volumes of sulphurous smoke. He estimates the depression of 

 the ancient crater at not less than 1,000 feet. The summit area is 

 a crescent in shape, half a mile in length and from three to fifty 

 feet wide. It is a fearful place ; on the north side is a precipice 



