374 APPENDIX TO PARTS I AND II. 



detail. No satisfactory means was originally devised, as a part of the instrument, for 

 accurately locating the horizon upon the paper ; but fortunately several of the points, 

 at which the fullest or most interesting profiles were drawn, were also occupied by Prof. 

 E. C. Pickering with the micrometer level, thus supplying the missing data without re- 

 sort to extended calculations. 



With the exception of that from Monadnock, the profiles are published on a scale of 

 about five millimeters to the degree ; but the scale attached to each is intended to com- 

 pensate for unavoidable variations. To measure horizontal angles with the greatest 

 attainable accuracy, use an ordinary metric scale ; but in addition to the desired angle, 

 measure with it the angular distance upon the attached scale between two graduations 

 nearly under the two points. The difference between the nominal angular distance on 

 the attached scale and its measured angular distance, as given by the scale used, should 

 be applied, with the proper sign, as a correction to the angle measured upon the profile. 

 Horizontal angles may be conveniently measured to tenths of a degree. For readiness 

 of identification, the zero of the attached scale is made to coincide as nearly as may be 

 with the south, so that its readings shall give directly the geodetic azimuth. The pro- 

 file from Monadnock is on a scale of about one centimeter to the degree, or twice that 

 of the others ; but for the part of the view to the right of Belknap, the data are want- 

 ing for giving the precise scale. Also, the position of the horizon is not so well known 

 for the second lines of profile from Monadnock and Starr King, as for the others. On 

 the other hand, the distant view from Monadnock, extending between the Franconia and 

 Ossipee ranges, has received more careful treatment than anything else upon the sheet. 



Any identified point not on the sky-line may be found on the profile by means of its 

 vertical position, given before the name. For this purpose, mark off from the zero of 

 a short paper scale the distance between the horizon and the bottom of the profile, this 

 distance being shown at either end of the sheet. Then, if this mark be placed any- 

 where upon the bottom line (the scale running in the direction of verticals), the zero 

 will indicate the level of the occupied point ; and the vertical position of the point 

 sought may be read directly upon the scale. 



For indicating minor points, and also those whose names are ambiguous or little 

 known, it has been found expedient to use the notation adopted by the Appalachian 

 Mountain Club, and described in Appalachia, Volume I, page 7. This consists of a 

 capital letter followed by two numbers. The capital letter indicates one of twenty-six 

 sections into which the state of New Hampshire has been divided ; the number before 

 the period indicates a certain mountain in the section ; and the figure after the period 

 indicates a special summit of the mountain, as indicated upon the maps of the club, — 

 that is, different summits of the same mountain differ only in the last figure of the 

 designation. 



Distances, when given, are expressed in kilometres, the number being enclosed in 

 brackets. One kilometre is a trifle less than five eighths of a mile. 



Conspicuous unidentified points are arbitrarily lettered, for convenience in defining 

 future identifications. 



