EXPEDITION TO POINT HAKKOW, ALASKA. 447 



they do not affect the position of (lie magnets. The use of candles stuck iu wooden blocks is pref- 

 erable to lamps. 



When on boat or sledge .journeys the party will carry a chronometer, a small alt-azimuth 

 instrument with circles of about three inches diameter (as constructed by Fauth & Co., of Wash- 

 iugton. or by Casella, of London), provided with a magnetic needle, or compass mounted over its 

 vertical axis, and a dip circle. 



"OliNi'rnttiiiHN a/ Ihc permit ii/'iit station. Hourly observations will be made for declination and 

 diurnal variation with the magnetometer on three consecutive days about the middle of each 

 month ; besides these observations, extending over seventy-two hours, there will be made, at any 

 convenient intermediate time each day (of the three) one set of deflections, followed immediately 

 by a set of oscillations for the determination of the horizontal intensity. At Point Barrow tho 

 bifllar will be read immediately after the unililar. There will also be made at any intermediate 

 time each day (of the three) a set of dip observations.. In connection with the declination, the 

 mark will be read once each day (unless the instrument should accidentally be disturbed), but it 

 suffices to determine the magnetic axis of the declination magnet on one of three days. The 

 instrumental constants of the magnetometer will bo determined before leaving Washington, and 

 the observer will use the Coast and Geodetic magnetic blank forms for their records, or, in case no 

 special forms are provided, they will use small (octavo) note-books; they will also compute, as 

 soon as the observations are completed each month, the magnetic mean declination, diurnal range, 

 and turning hours; also the horizontal force in absolute measure (English units) and the dip, tabu- 

 lating the results for each day. 



"Extra observations on other than the three days about the middle of each month will lie 

 made during all occurrences of auroral displays, but as they are likely to be very numerous at 

 Point Harrow observers there may confine their extra observations to the more conspicuous dis- 

 plays only. On these occasions the declinometer (and the bifilar) at Point Barrow will be read 

 every 10 minutes or ofteuer, or less often, as the state of the needle may appear to demand, tho 

 object being to ascertain the relation and establish a connection between the appearance of the 

 aurora and the motion of the magnetic needle. 



" When landing on a boat journey or during a sledge journey, at suitable stations (not less than 

 10 or 15 miles apart), the time, latitude, and azimuth will be determined by the alt-azimuth instru- 

 ment and the declination by the same instrument (the hour and minutes of the observation is to 

 be noted iu order that the diurnal variation may be allowed for); the dip will also be observed, 

 and in case time is pressing, reversal of circle, reversal of face of needle, and reversal of polarity 

 of needle maybe dispensed with, but the needed corrections to the result from the single position 

 of the instrument or needle must be ascertained at the permanent station. Observations of de- 

 flections vith magnetic needle and with weights will be made with the dip circle as arranged for 

 relative and absolute total force, the data for the latter to be supplied at the permanent station. 



" 1 1 is highly desirable, especially in the case of the Lady Franklin Bay party, that all stations 

 within reach and formerly occupied by other parties for magnetic purposes, be revisited in order 

 to furnish material from which to deduce the secular change during the interval; besides all 

 opportunities should be taken when landing on the way up, to secure observations for declination, 

 dip, and intensity ; tho latter, best by oscillations of the intensity magnet. The winter quarters 

 of the late English expedition should be connected magnetically with the present quarters. 



'All magnetic observations will be made on Gottingen time, as provided for by the Hamburg 

 Conference.* 



'All magnetic work will be kept strictly in conformity with 'Notes on measurements of 

 terrestrial magnetism,' United States Coast Survey, Washington, D. C., 1877.1 and other records in 

 connection therewith should be equally clear and complete, and all computations should be made 

 by the observer in separate books. Duplicates of all records will be made, compared with the 

 original, and the latter returned annually,! if practicable, to the Superintendent of the Coast and 

 Geodetic Survey, Washington, I). C. The observers should also provide themselves with copies 



* This s. ntenee I lincl added in original report. [Sell.] 



t A new edition. 1 lie third, h;is since ;i|ipe;ired iu Appendix No. s, C'o:is[ and (leodrtie Sm -, T> Report I'm l- ; -l. 



; It was then supposed that the partie- \vonhl remain out lor three years'. 



