224 ANNUAL EECOKD OF SCIENCE AND INDUSTRY. 



* largest triangles ever observed, and clearing at a single step 

 the interval between the Coast range and the Sierras, one of 

 the diagonals in the quadrilateral being one hundred and 

 sixty-two miles long. This is part of a general scheme for 

 uniting in one system the Atlantic and Pacific coast triangu- 

 lations which about five years since was authorized by Con- 

 gress ; and here good progress lias been made, not only by 

 the requisite reconnoissance, but by actual triangulation. 



On the southern branch of this transcontinental triangu- 

 lation, the work has been actually executed from Atlanta 

 across Georgia and Alabama, and laid out to the vicinity of 

 Memphis. On the northern branch the scheme has been 

 perfected to the Ohio River, and from a central point near 

 St. Louis the triangulation has been carried westward half- 

 way across Missouri, while the reconnoissance has been ex- 

 tended eastward across Illinois. Numerous interior posi- 

 tions have been accurately determined in latitude and lon- 

 gitude, by astronomical observations, and a line of levels of 

 extreme precision between the two oceans begun. In au- 

 thorizing this work, Congress provided that by furnishing 

 the general triangulation, the aid of the Coast Survey or- 

 ganization should be given to those states that have provid- 

 ed for a topographical survey of their area. Under this 

 provision, triangulation has progressed in the states of New 

 Hampshire, New Jersey, Pennsylvania, Tennessee, Kentucky, 

 and Wisconsin. It is to be regretted that all this work, 

 looking directly towards a comprehensive scheme of a gen- 

 eral trigonometrical survey of the whole country, has been 

 interrupted by the failure of the last Congress to provide 

 any means for its prosecution. 



AVe cannot leave the Coast Survey without adverting to 

 its perfect and beautiful maps, its "Coast Pilot," its tide-ta- 

 bles, published, annually, and its magnetic charts; but any 

 particular enumeration of these and other matters would 

 carry us too far away from our present purpose. 



Last spring the government instituted, under the Depart- 

 ment of the Interior, an Entomological Commission, whose 

 special object was to make a thorough examination into the 

 locust evil and suggest remedies. Messrs. Piley, Packard, 

 and Thomas were appointed, and divided between them the 

 possible locust area, or the region w T cst of the ninety-fourth 



