144 Transactions of the American Institute. 



this book I found my text, and thus it reads : " Magnus magnes ipse 

 est globus terresi^is" which, being interpreted, is, " the earth itself is 

 a great magnet." 



Those who will examine this remarkable book of science cannot 

 fail to observe how skillfully Gilbert handles the experimental or 

 inductive method of research in arriving at the facts and the laws of 

 magnetism ; and if he cannot be styled " the Father of Inductive 

 Philosophy," he can, at least, lay claim to our most hearty admiration 

 for the brilliant manner in which he (with Galileo) first, by his dis- 

 coveries, demonstrated the practical value of this injunction of Bacon 

 — that by observation and experiment alone can the mind of man 

 arrive at a knowledge of the laws which rule the universe. 



That the earth itself is a great magnet, I propose as the problem to 

 be solved before we separate, but the short duration of a single lec- 

 ture will permit me to attack this problem only in the most general 

 manner ; and having proved that the earth is a magnet, it will not be 

 allowed me the pleasure to examine with any minuteness the charac- 

 teristics of this huge lodestone, such as the position of its poles, the 

 path of its equator* and those mysterious variations on the directions 

 and intensity of its force, which latter seem to be in subjection to 

 emanations from the sun — changing with the apparent daily and 

 yearly revolutions of that orb, and pulsating in sympathy with the 

 huge waves of fire which sweep over its surface ; for it seems prob- 

 able that, on any sudden agitation of the sun's surface, the magnetism 

 of the earth receives a profound disturbance in its equilibrium, caus- 

 ing fitful tremors in the magnets of our observatories and producing 

 those grand outbursts of the polar lights, whose lambent flames 

 dance in rhythm to the quivering needle. 



The earth itself is a great magnet. Of the earth, you know ; but 

 what is a magnet % I hold one in my hand as given us by nature. 



gave steel the preference over soft iron." Prof. John Robison— A System of Natural Philosophy. 

 London, 1822: page 209: "It is not saying too much of this work of Dr. Gilbert's to affirm that it 

 contains almost everything we know about magnetism. His unwearied diligence in searching every 

 writing on the subject, and in getting information from navigators, and his incessant occupation in 

 experiments, have left very few facts unknown to him. We meet with many things in the writings 

 of posterior inquirers, some of them of high reputation, and of the present day, which are published 

 and received as notable discoveriespbut are contained in the rich collection of Dr. Gilbert. Dr. Gil- 

 bert's book, although one of those which does the highest honor to our country, is less known in 

 Britain than on the continent. Indeed, we know of but two British editions of it, which arc both 

 in Latin ; and we have seen five editions published in Germany and Holland before 1628. We 

 earnestly recommend it to the perusal of the curious reader." Also, refer to Dr. Young's Lectures 

 on Natural Philosophy, 1845: page 583; to Sir D. Brewster, Treatise on Magnetism, Edin., 1851 : 

 page 9 ; Whewell, History of the Inductive Sciences, volume iii, page 37, et seq. 



