448 Tlie Surveys of India. [Oct., 



Franklin Institute,' published in Philadelphia. This I did, for 

 the first time, on the 9th of that month, finding a fair agreement 

 between the southern portions of his prominences 5 and 10, and 

 the dark bands given in my sketch. I have, therefore, little doubt 

 but that in locating these dark intervals in my original sketches, I 

 intended to place the western one near 285°, and the eastern one 

 near 120°, great exactness not being obtainable in the few moment^ 

 given to the observation. In speaking of these bands as dark, I 

 would be understood only as meaning that they were sufficiently so 

 to be readily seen. 



A comparison of the Des Moines and Ottumwa pictures of the 

 " anvil " protuberance gives the following measurements. It will 

 be noticed that the figures are somewhat in excess of those obtained 

 from the last totality picture made at Burlington. 



" Miles. 



Extreme length of the "anvil" 265 or 119-800 



„ „ base of the "anvil".. .. 205 „ 92*500 



Greatest altitude above the sun's surface . . . . 81 „ 36 " 500 



Thus if, as is probable, the entire protuberance was not visible, 

 its base being beyond the sun's limb, we have a bright cloud in the 

 solar atmosphere nearly, if not quite, equal in volume to the planet 

 Jupiter, and which in the direction of its length would suffice to 

 reach more than half way to the Moon in her perigee. 



THE SUEVEYS OF INDIA 



II. THE TEIGONOMETEICAL SUEVEY. 



( With a Sketch-map.) 



By F. C. Danvees, A.I.C.E. 



The surveys of India may be divided into two classes — viz. the 

 Great Trigonometrical, and the Geological. In connection with the 

 former, other minor operations are undertaken under the title of 

 topographical and revenue surveys, to which we shall refer more 

 particularly in due course. 



The idea of a great trigonometrical survey of a country, to be 

 undertaken by the Government of that country, was first conceived 

 by General Watson, at the suppression of the rising in Scotland in 

 1745. The execution of it was committed to General Eay, and 

 was originally intended to extend no farther than the disaffected 

 districts of the Highlands. The design, however, was subsequently 

 enlarged, and the grand trigonometrical survey of Great Britain 



