384 Bibliography. 



by repeated simultaneous observations of the best barometers, the true 

 elevation of all the important mountain elevations, which constitute 

 such an important feature in New Hampshire scenery, and also, by 

 proper astronomical obsei-vations, to fix their geographical position. 

 Mount La Fayette, the most elevated point in the group, commonly 

 known as the Franconia Notch, was found to be five thousand and sixty 

 seven feet high, and its latitude, N. 44° 8' 59".4. Mount Washington, 

 the highest point in New England, was measured with eveiy precau- 

 tion to insure accuracy, and an interesting account is given in the re- 

 port of the modes adopted to ensure this end. The result wais, that 

 the summit of Mount Washington is N. 44° 16' 34".48 ; and the 

 height, as ascertained by a series of barometrical and thermometrical 

 observations, made under the most favorable circumstances, during 

 twelve hours, was six thousand two hundred and twenty six feet above 

 the high-water mark in Portsmouth harbor ; the same, calculated by a 

 series of observations, was six thousand two hundred and twenty eight 

 feet, making but two feet difference in the elevations, and in single 

 observations the difference is but six feet. 



The most interesting mineralogical discovery made during this ex- 

 ploration, was that in the town of Jackson, of a vein of oxide of tin, 

 in a powerful lode of arsenical pyrites. This is the first instance 

 of the occurrence of this metal in America in any tangible quantity, 

 and although the amount of the tin hitherto observed is not great, yet 

 the discovery, in its indications, may be looked on as one of the most 

 valuable metallurgic observations yet made among us. 



Dr. Jackson also mentions the occurrence of a mineral at Unity, to 

 which he gives the name of chlorophyllite, and is inclined to consider 

 as new ; it will be seen by reference to page 357 of the present num- 

 ber, that this opinion is there discussed. 



The chemical department of the report evinces, as usual, much ac- 

 tivity and patience in the laboratory, and when the final report appears, 

 we hope to transfer some of the valuable results to our pages. 



15. Final Report on the Geology of Massachusetts; hy Edward 

 Hitchcock, LL. D. 2 vols. 4to. pp. 831, 54 plates. Amherst, J. S. & 

 C. Adams; Northampton, S. Butler. 1841. — It is with great pleasure we 

 announce at last the appearance of this work, the most elaborate and 

 laborious treatise on the subject of geology which has yet appeared in 

 America, and the first (except Prof. H. D. Rogers' report on New Jer- 

 sey) of that series of final reports which are to form the grand sum- 

 ming up of the twenty state surveys now in progress or just completed. 



If we reflect that the vast mass of facts and information of various 

 descriptions, and the reasonings and inferences contained in these vol- 



I 



