160 EXPLOITATIONS ACROSS THE GREAT BASIN OF UTAH. 



gives a resulting longitude for Great Salt Lake City, according to our observations, of 

 111° 55' 00", differing from Fremont's, in his second expedition, only 26", and from 

 his determinations in his third expedition, 11' 08". This result, I think, is corrobora- 

 tive of the accuracy of his longitude, as determined in his second expedition, and of 

 our own.* 



Again, Fremont makes the longitude of the most northern bend of Walker's Eiver, 

 in his third expedition, 119° 05' 23". We make the longitude of this same bend, by 

 observations of east and west stars and lunar distances, 118° 56' 00", differing from 

 his 09' 23", but as our station appears to have been about 2' farther west than his, the 

 disagreement between us amounts to about 11' 23".f 



Thus far it will be noticed our disagreements have been 11' 08" at Salt Lake City, 

 and 11' 23" at the most northern bend of Walker; but from this point westward, within 

 a measured distance, by odometer, of only 60 miles along our route, and a difference 

 of longitude of only 46' 50", our longitudes become suddenly so variant, as at the 

 junction of the east and west branches of Carson River, at the base of the Sierra 

 Nevada, to make us differ as much as 21' 30". Supposing, possibly, that I might have 

 been in error, I have examined my map and notes critically upon this point, and feel 

 confident that this suddenly enlarged discrepancy is not due to any errors we have 

 committed. Besides, what makes me more disposed to think that the error does not 

 lie with us is that Mr. George II. Goddard, the civil engineer who was intrusted by the 

 State of California, in 1855, with the determination of the eastern boundary of that 

 State, makes the longitude of Genoa 119° 48' 25", | or 7' 55" greater than mine, while 

 Fremont's of this point, so far as it can be determined from its proximity to the junc- 

 tion of the east and west forks of Carson River, laid down on his map of his expedi- 

 tion of 1845-'46, is 21' 30" greater. 



I have been thus particular in giving the points of difference between Fremont's 

 longitudes and my own, from the circumstance that they have been hitherto regarded 

 as correct, and succeeding explorers have referred their longitudes chronometrically to 

 them as standards. 



Before dismissing this subject, I cannot but bring to the attention of the Bureau 

 the great importance of sending into the field, and of officers intrusted with expeditions 

 of securing, the very best chronometers and astronomical instruments which can be 

 purchased. A hundred dollars or more on a chronometer or other field-instrument may 

 insure results which may be reliable and permanent; whereas a false economy which 

 would be content with anything less will frequently jeopard the results of the whole 

 expedition, and cause the expenditure of thousands of dollars, as well as the opportu- 

 nity of gaining correct geographical knowledge, to have been entirely nugatory. 



I would also state that the very best possible way we found of carrying our 

 chronometers (four in number) was to place them in a soft-cushioned box prepared 

 for the purpose/and to strap the box on the middle seat of an easy ambulance or spring- . 

 wagon. Our box-chronometer we allowed to play freely in the gimbals, only placing 



'My latitude of Great Salt Lake City differs froniFrdnjont's 10" ; from Stansbury's, 3". 

 t Onr latitude of this bend agrees within 26". 



t Mr. Goddard appears to ha\ ■• beei - „t e astronor 



See Annual Report of Surveyor-Geuer i i-Wt, 



