272 CARNEGIE INSTITUTION OF WASHINGTON. 



magnetic forces. The first circuit, passing as it does along the 

 American and Asiatic coasts, will yield especially interesting results 

 in this respect. Thus, for example, along the Aleutian Islands 

 marked local disturbances will be revealed. Reports are received 

 frequently from mariners in this region regarding the unsatisfactory 

 behavior of the compass ; it is therefore greatly to be desired that a 

 magnetic survey of the waters in this region be made with all neces- 

 sary detail. 



The letters appended will give further information regarding the 

 plan, and will give evidence of the opinions held by those competent 

 to judge. 



\Letter from Capt. E.. W. Creak to Dr. Bauer. ~\ 



q Hervey Road, Blackheath, London, S. E., 



August ji, igo4. 



My Dear Dr. Bauer : The North Pacific Ocean is, with the 

 exception of the voyage of the Challenger, nearly a blank as regards 

 magnetic observations, and I therefore think the magnetic survey 

 you propose will be of great value. 



In view of a sailing ship being emploj^ed, the route marked out 

 in the letter (of which you have sent me a copy) is, I think, well 

 thought out as regards winds, but I would, if I could, have a larger 

 ship than the one proposed, of 600 tons. However, all can be done 

 in a vessel of 600 tons, if of the proper form — a fast clipper is not 

 wanted, but rather a good, wholesome, steady ship in a seaway. 



There is one point which I may have mentioned once before, but 

 will bear repetition. The position selected for the magnetic instru- 

 ments should be entirely free, if possible, from any vertical force in 

 the ship. This especially applies to a sailing ship, which under 

 action of the sails is liable to a constantly varying angle of inclina- 

 tion, and where the vertical force of the ship causes a constantly 

 varying heeling error in the magnetic instruments. 



The absence of any vertical force in the ship renders the obser^^a- 

 tion taken on board free from any reference to the shore as regards 

 declination and inclination, the effects of horizontal disturbance, if of 

 moderate amount, being easily accounted for by swinging at sea as 

 opportunity affords. 



Ivastly, as to a similar close examination to that proposed for the 

 North Pacific being subsequently carried out in the South Pacific, 



