Lovering and Bond on Magnetic Observations at Cambridge. 11 
to this rigid system, were originally expected to extend over three 
years. When the materials thus patiently gathered from so many 
remote sources shall be collected, they will pass into the hands of 
competent persons to furnish the elements for a complete Theory of 
the earth’s Magnetism ; and any attempt to pronounce at this time 
positively on this great subject would justly be regarded as prema- 
ture. But it is equally certain that there are secondary questions, 
of considerable intrinsic importance, which may be discussed now 
as well as at any time; the settlement of which will be facilitated by 
an occasional publication of portions of the regular magnetic obser- 
vations. Much light may be thrown upon the general subject by a 
comparison of partial results; and parts of a well-concerted plan to 
which no present objection appears may prove useless in fact, and 
be either remodelled or superseded by other observations which ex- 
perience has shown will serve a better purpose. Moreover, the sub- 
ject of Terrestrial Magnetism deeply engages the attention of the 
scientific world, and many not actively engaged in the research will 
be anxious to understand the progress of a scheme which promises 
to shed light upon this complex problem. In this great country it 
is highly important that something should be done to awaken the 
attention of individuals and of the American nation ; and to bespeak 
their bounty in favor of a scientific enterprise which has received 
the highest patronage of European and other governments. The 
commercial prosperity no less than the interests of pure science 
will be affected by the spirit and liberality with which this bold pro- 
ject is sustained and conducted. It is hoped that the present pub- 
lication may not prove useless for some of these purposes. A writer 
in the “London Quarterly Review,” after speaking of the materials 
that will be collected at head-quarters, by three years’ contribution, 
proceeds thus: “ Voluminous beyond all former precedent as the 
