64 
FOREST AND STREAM 
[Jan. 9, 1909. 
netic Tables and Magnetic Charts” for 1905, by 
Dr. L. A. Bauer. But this line has for many 
years been moving south-'westward; how long 
this motion will continue is not known. It may 
be stated that the true North Pole and the mag¬ 
netic North Pole are not identical; in fact, while 
the true North Pole is stationary, except for the 
very small motion recently discovered by astrono¬ 
mers, the magnetic pole appears subject to con¬ 
siderable motion with the lapse of time, the 
actual path being as yet not known on account 
of lack of data covering a sufficient period of 
lime. There is little doubt, however, that the 
motion of the “line of no variation” in the 
United States bears some fixed relation to the 
motion of the magnetic North Pole. Thus, in 
addition to the compass direction varying from 
place to place, it even changes at the same place 
by an amount sufficient to be taken into account 
by him who uses the compass in surveying a 
field or in navigating a vessel. 
Alexander von Plumboldt recognized the im¬ 
portance of terrestrial magnetism and referred 
to it in his “Cosmos.” Pie suggested that four 
times in every century an expedition of three 
ships should bq sent out to examine as nearly 
as possible, at the same time the state of the 
magnetism of the earth, so far as it can be in¬ 
vestigated in those parts which are covered by 
the ocean. This plan of Humboldt’s never came 
to a realization, and instead the work heretofore 
has consisted of more or less isolated and in¬ 
complete surveys independently undertaken by 
various nations and distributed over a great 
many years. Not even for a single epoch has 
it been possible to construct magnetic maps on 
the plan of concerted action, to say nothing of 
the impossibility of drawing them for several 
epochs, twenty-five or thirty years apart. 
Some notable surveys were made, among them 
being the memorable Antarctic Expedition of 
Sir James Clarke Ross (1839-45) which threw 
much light on the magnetic conditions of the 
south polar regions, and determined empirically 
the approximate position of the magnetic South 
Pole. The Challenger Expedition (1872-76) was 
productive of a fund of valuable information in 
connection with the magnetic conditions over the 
oceanic areas, along the paths traversed by this 
noted expedition; but all the work done covered 
hardly more than one-tenth of the navigable 
waters of the earth. 
It was, therefore, high time that a systematic 
survey or a series of surveys should be under¬ 
taken to determine the magnetic conditions all 
over the deep water seas, and something over 
four years ago the Carnegie Institution of Wash¬ 
ington undertook this task. Accordingly a de¬ 
partment of research in terrestrial magnetism 
was organized and the entire work was placed 
under the directorship of Dr. L. A. Bauer, for¬ 
merly in charge of the magnetic survey of the 
United States under the Coast and Geodetic 
Survey. 
The first step in the ocean work was to make 
a magnetic survey of the Pacific Ocean where 
little had been done, except shore observation 
on some of the islands and along the coasts, 
since the notable voyages of Challenger and of 
Gazelle (a German expedition) more than thirty 
years ago. Observations were made from the 
converted wooden yacht Galilee which, between 
Aug. I, 1905. and May 31, 1908—or in somewhat 
less than three years—made three successive 
voyages in the Pacific, tracing the great circle 
route, zig-zagging in and out of the islands and 
covering with a network of tracks all the places 
left uncovered by the Challenger; the total length 
of these cruises amounted to over sixty thou¬ 
sand miles. The most northerly point visited by 
the Galilee was Sitka, Alaska, and the most 
southerly one, Lyttleton, New Zealand. During 
the period 1906-08 she was commanded by W. 
J. Peters, who is likewise to be in charge of the 
new vessel. 
This is only a good beginning of the work. 
The institution has already made magnetic ob¬ 
servations in many parts of the globe and now 
has two expeditions in Africa, has just sent an¬ 
other to China, has one in Persia and Asia 
Minor, and has covered a part of South and 
Central America, and British North America 
and Greenland. It is estimated that a magnetic 
survey of the world can be completed in about 
ten years more. 
With the experience gained with the Galilee, it 
was proved that, for the most economical, ex¬ 
peditious and satisfactory execution of this work 
it would be advantageous to have constructed a 
thoroughly non-magnetic yacht with auxiliary 
power and every detail arranged specifically for 
making magnetic observations, which consist of 
three kinds—the magnetic desclination or varia¬ 
tion of the compass needle; the dip of the needle 
toward the magnetic pole, and the force acting 
on a magnetized needle. The latter element is 
determined, for example, by timing the swing 
of the compass needle with a chronometer, and 
by the method of observations technically known 
as deflections. 
The building of such a vessel having been au¬ 
thorized by the Carnegie Institution of Wash¬ 
ington, Henry J. Gielow, of New York, the well- 
known naval architect, was consulted and the 
preparation of plans and specifications entrusted 
to him. On account of the vessel being required 
to be practically non-magnetic, many difficulties 
were encountered and overcome. On Dec. 9 the 
Carnegie Institution of Washington entered into 
contract with the Tebo Yacht Basin Company, 
of Brooklyn, N. Y., for the construction of this 
magnetic survey vessel, to be named the Carnegie. 
This vessel deserves more than a passing 
notice, as it will be the first vessel in the con¬ 
struction of which iron and steel and other mag¬ 
netic metals will practically have no part; in 
other words, with the exception of thin cast- 
iron liners in the cylinders of the bronze internal 
combustion engine, and the steel cams necessary 
NONMAGNETIC YACHT CARNEGIE-NOW BUILDING FOR SCIENTIFIC RESEARCH. 
