556 THE POPULAR SCIENCE MONTHLY. 



is a question of great difficulty ; and the conjecture made is, that it is 

 an inflow of the cold water from the vast area of the antarctic." 



The geographical work of the United States has been more limited 

 than usual, owing to delay and smallness of appropriations. The 

 Coast Survey continues its work : in the Gulf of Mexico careful sound- 

 ings have been made, and observations on the temperature of the 

 water and the flow of currents, which will throw light on the Gulf 

 Stream. Triangulations were pushed eastward from the Pacific Coast 

 Range to the Sierra Nevada, some of the triangles observed having 

 sides over 150 miles long; a series of telegraphic determinations of 

 longitude have been made for the purpose of correcting our charts of 

 the West India Islands, one point at least having been located on 

 eacli island. Triangulation along Lakes Ontario, Erie, and Michigan, 

 has been continued, the topography of Niagara River completed, 

 many points determined for the State survey of Michigan, and the ele- 

 vation of the Great Lakes newly determined. Lake Ontario is found 

 to be 247.25 feet and Lake Erie 573.58 feet above mean tide at New 

 York. Reports of geographical and topographical work in Montana, 

 the Yellowstone Park, Southern Colorado, Northern New Mexico, 

 and Arizona, have been issued. The geographical surveys west of 

 the 100th meridian, under Lieutenant Wheeler, have been continued. 

 About 25,000 square miles were traversed by the various parties. 

 Some interesting Spanish mines were found in New Mexico. A sur- 

 vey was carried on in the neighborhood of Lake Tahoe, in California. 

 The depth of the lake was found to exceed 2,200 feet. The examina- 

 tion of the Colorado River, with reference to determining the practi- 

 cability of diverting it from its channel to irrigate the deserts of 

 Southeastern California, has been completed. The lowest part of the 

 desert is 200 feet below the sea, and it was found that an area of 1,600 

 square miles could be flooded; but constantly-shifting sands would 

 make it a continual expense, and the evaporation from the surface of 

 such a lake would exceed the water flowing in the Colorado in a dry 

 season. Thirteen atlas sheets of Lieutenant Wheeler's survey have 

 been issued ; they are upon a scale of eight miles to the inch, and cover 

 a large part of Nevada, Utah, Arizona, New Mexico, and Colorado. 

 The survey of the Territories under Profs. Hayden and Powell was 

 carried on, and much has been learned of the region embracing Colo- 

 rado, Utah, and Southeastern Nevada. A triangulation party climbed 

 and measured Blanco Peak, near Fort Garland, in Colorado, which, if 

 not the highest, is next to the highest peak in the Rocky Mountains. 

 It is 14,464 feet high. Over fifty of the most elevated peaks in that 

 range are in the State of Colorado, running from 14,000 to 14,500 feet, 

 so close that the utmost care has been required to determine which is 

 the highest. 



Eastern Utah was surveyed from the Colorado River to and over 

 the Wahsatch Mountains between parallels 38 and 39 15'. The region 



