EXPEDITION TOWARD THE NORTH POLE. 367 



INSTEUOTIONS. 



GENERAL DIRECTIONS IN REGARD TO THE MODE OF KEEPING 



RECORDS. 



Records of observations. — It is of the first importance that in all in- 

 strn mental observations the fullest record be made, and that the original 

 notes be preserved carefully. 



In all cases the actual instrumental readings must be recorded, and 

 if any corrections are to be applied, the reason for these corrections 

 must also be recorded. For instance, it is not sufficient to state the 

 index error of a sextant; the manner of ascertaining it and the readings 

 t;tken for the jjurpose must be recorded. 



The log-book should contain a continuous narrative of all that is done 

 by the expedition and of all incidents which occur on shipboard, and a 

 similar journal should be kept by each sledge party. The actual obser- 

 vations for determining time, latitude, the sun's bearing, and all notes 

 having reference to mapping the shore, soundings, temperature, «&c., 

 should be entered in the log-book or journal in the regular order of 

 occurrence. When scientific observations are more fully recorded in the 

 note-books of the scientific observer than can be conveniently transcribed 

 into the log-book, the fact of the observation and reference to the note- 

 book should be entered. 



The evidence of the genuineness of the observations brought back 

 should be of the most irrefragable character. No erasures, wliatever,, 

 v/ith rubber or knife, should be made. When an entry requires correc- 

 tion, the figures or words should be merely crossed by a line, and the 

 correct figures written above. 



J. E. HlLC^AED. 

 ASTRONOMY. 



jisirono'tuicalohscrvations. — Oneof the chronometers, the most valuable, 

 if there is any difference, should be selected as the standard by which 

 all observations are to be made, as far as practicable. The other 

 chronometers should all be compared with this every day at the time 

 of winding, and the comparisons entered in the astronomical note- 

 book. 



When practicable, the altitude or zenith distance of the sun should 

 betaken four times a day — morning and evening for time; noon and 

 midnight for latitude. The^tlironometer or watch times of the latitude 

 observations, as well as of the time observations, should always be 

 recorded. Each obsi'rvation should ahvays be repeated at least three 

 times in all, to detect any mistake. 



When the moon is visible, three measures of her altitude should be 

 taken about the time of her passage over each cardinal point of true 

 bearing, and the chronometer time of each altitude sbould be recorded. 



As the Greenwich time deduced from the chronometers will be quite 



