338 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



Vienna Exposition, lias now been lithographed, and is for 

 sale. It is on a scale of 1:355,000. 



Dr. Crevaux, in 1877, made a most arduous and interest- 

 ing exploration of the interior of French Guiana. Accom- 

 panied at first by two missionaries, the obstacles to travel 

 soon caused his companions to return, and Dr. Crevaux, with 

 one negro, traversed about 1500 miles of territory, 675 miles 

 of which was new ground. After ascending the river Maro- 

 ni, he crossed the northern slope of the Tumac Huraac chain 

 of mountains, returning by the southern slope, and, descend- 

 ing the river Yary, reached the Amazon after a march of 

 142 days. Numerous explorers have in vain tried, during 

 the last three centuries, to cross the Tumac Humac range of 

 mountains; and, in addition to his success here, Dr. Crevaux 

 has delineated correctly, for the first time, the course of the 

 river Yary. He has been, during the past year, and is now, en- 

 gaged in fresh explorations. under the direction of the French 

 authorities. Leaving Paramaribo on August 8, he ascended 

 the Oyapock River to its source, intending to cross the moun- 

 tains again and to attempt to reach the head-waters of the 

 Surinam River. A recent letter from him, however, indicates 

 that he may return by way of the Purus and Amazon rivers. 



Two attempts have been made during the last year to ex- 

 plore the Roraima range of mountains lying between Guiana 

 and New Granada. The first attempt was made by Messrs. 

 Eddington and Flint, who, after an arduous journey, reached 

 the base of the overhanging cliff's, 7000 feet above the sea, 

 and found further progress impossible. A second attempt 

 was made by Mr. Boddam-Whetham, who, with a small par- 

 ty, ascended the Essequibo, Mazaruni, and Carubung rivers 

 to the Macrebah Falls. Thence by a toilsome march they 

 approached the mountains, making the best of their way 

 towards Mount Roraima. This huge pile is described as a 

 parallelogram, eight miles by six, rising in a precipitous 

 wall nearly 2000 feet above its lower portion. Eight days 

 were spent in vainly trying to climb it. There is some rea- 

 son to believe that a lake exists on the top of the plateau, 

 which is well wooded, but the question of its existence has 

 yet to be decided. 



In Brazil the explorers connected with the Madeira-Mamo- 

 re Railway are busily engaged in examining the surrounding 



