Makers of Electricity

us and C

erve as models of excellence. Their poets and historians continue to be read for the sake of the narrative and beauty of the s

ements," of Apollonius and his Conics, of Eratosthenes and his determination of the earth's circumference, of Archimedes and his mensuration of the sphere, and of the inscription on Pl

ted, as time is an essential element in experimentation and in the collection of data, bo

with which we are concerned at present, the attractive property was the only one known to ancient philosophy for a period of s

atura Rerum" contains his speculations anent the magnet, together with certain observations which show that the poet was not only a thinker, but somewhat of an experimenter as well. Thus he

riment which is frequently referred to in works on magnetic philosophy. It reads: "Thus have I seen raspings of i

razen vessel

amothrace, or

he valid iron

w, the magnet p

y the various names of magnetic figures, magnetic curves, magnetic spectrum. We do not, however, share this view, because we see no adequate resemblance between the positions assumed by the bristling particles of iron in the one case, as described by the Roman

use of filings and employing them to show the direction of the resultant force at any point in the neighborhood of a magnet, belongs to Cabeo, an Italian Jesuit, who described and illustrated it in his "Philosophia Magnetica," published at Ferrara in the y

hollow rings of iron which, for the amusement of the crowd, the jugglers

e lodestone,

potent virtues

ts, they view wit

id of hinges,

in we hold of

tone-the stone t

ring and owns

ve, the ones b

circle downwar

ir disports the

nes quoted above or in any other lines of his great didactic poem to indicate that he was aware of the remarkable difference which there is between

ug out of the tomes of ancient writers which gained credence and popularity, partly by reason of the fondness of the

kinds of lodestones, one of which was said to repel iron just as the normal lodestone attracts it. Needless to say that

etite in the vault of an Alexandrian temple for the purpose of holding an iron statue of Queen Arsinoe suspended in mid-air. Of like fabulous character is the oft-repe

nsion of his coffin in the "Holy City" of Mecca, contains a twofold error, one of place and the other of position. By a recent (1908) imp

ladius (368-430), writing on the Brahmans of India, tell how certain magnetic mountains were said to draw iron nails from passing ships and how wooden pegs were substituted for nails in vessels going to Taproba

ers for the relief of headache; magnetic applications to ease toothaches and dispel melancholy; magnetic nostrums to cure the dropsy, to quell disputes and even reconcile husband and wife. No less fictitious was the pernicious effect on the lodestone attributed in the early days of the mariner's compass to onions and garlic; and yet, so deeply rooted was the belief in this figment that sailors, while steering by the compass, were forbidden the use of these vegetables lest by their breath

gnet, in virtue of which a freely suspended compass-needle takes up a definite position relatively to the north-a

who heard of it from their Mussulman foes. These, in turn, derived their knowledge from the

ouvère Guyot de Provins,[2] who wrote, about the year 1208, a satirica

loy an art which

stone an

n joins itse

ter applying

he latter

simply in

straw make

point tur

r with suc

n will eve

it ever

ea is dark

s neither st

ut a light

fear of losi

urns toward

ariners a

w the ri

rt which c

and princes, and even the reigning pontiff himself, all of whom should be for their subjects, according

ife retired from a world which he despised, and ended his day

Guyot, is found in the Spanish code of laws known as Las Siete Parti

em where they go alike in bad seasons as in good; so those who are to give counsel to the king ought always to guide themselves by justice, which is the conne

thirteenth century in order to show how little was known about the magnet and how cru

for some years, wrote his "History of the Orient"

rns towards the north star, so that such a needl

s to indicate that even then the compass was

stinian Abbot of Cirencester

e and turn until the point looks to the north; the sailors will thus know how to direct t

roduction of this mode of suspension, the needle was floated on a straw, in a reed, on a piece of cork or a strip of wood, all of which modes of fl

to the new magnetic knowledge in his "Livres dou Treso

es; and each of the two parts of the lodestone directs the end of the needle that h

as not got the philosophy of the needle quite right in this passage; for the part that has been touched by the north end of a lodestone

luence on the compass-needle that ema

art of one of

oice that, nee

ar in turnin

e, XII.

ensive travels as well as for the zeal which he displayed in converting the African Moors. Lully writes in his "De Contempl

that unlike poles attract while like poles repel each other. Bacon further remarks, by way of corroboration, that if a strip of iron be floated in a basin, the end that was touched by the lodestone will follow the stone, while the other end will flee from it as a lamb from the wolf. There is, however, an earlier recognition known of the polarity of the lodestone; for Abbot Neckam, fifty years before, called attention to the dual nature of the physical action of the lodestone, attracting in one part (say) by sympathy and repelling at the other by antipathy. It was the common belief in Bacon's time and for centuries after, that the compass-needle was directed by the pole-star, often called the sailor's star; but Bacon himself did not think so, preferring to believe with Peregrinus, that it was controlled not by any one star or by any one constellation, but by the entire celesti

magnet is not to be sought in the remote star depths at all, but in the earth itself, the whole terrestrial globe acting as a colossal magnet, partly in

en in the height of its fame. His reputation for mathematical learning and mechanical skill crossed the Channel and reached Friar Bacon in the University of Oxford. In his "Opus Tertium," the Franciscan Friar records the esteem in which he held his Picard friend, saying: "I know of only one person who deserves praise for his wor

lso in the working of minerals; he is thoroughly acquainted with all sorts of arms and implements used in military service and in hunting, besides which he is skilled in agriculture and also in the measurement of lands. It is impossible to w

the method what you will, inductive, deductive or both, the method advocated by the Franciscan friar of the thirteenth century was the one followed at all times from Archimedes to Peregrinus and from Peregrinus to Gilbert, none of whom knew anything of Lord Bacon's pompous phrases and lofty commendation of the inductive method of inquiry for the advancement of physical knowledge. Be it said in passing, that Bacon, eminent as he undoubtedly was in the realm of the higher philosophy, was, neverth

of the physicist to that of the philosopher, from correlating facts and phenomena to the discovery of the laws which govern them and the causes that produce them. Furthermore, he was in no hurry to let the world know that he was grinding lodestones one day and pivoting compass-needles th

manner of Archimedes; but though he spent three years on the enterprise and a correspondingly large sum of money, we are not told by Friar Bacon, who mentions the fact, what measure of success was a

ccomplishment. For this purpose, he used 168 small mirrors in the construction of a large concave reflector, with which he ignited wood at a distance of 150 feet and succeeded in melting lead at a distance of

travel and adventure, he took the cross in early life and joined one of the crusading expeditions of the time. That he went to the land of the paynim, we have no direct evidence; but we

called the engineering corps of the army, and was engaged in fortifying the camp and constructing engines of defense and attack. Unlike his companions in arms, Peregrinus does not allow himself to be wholly absorbed with military duties, nor do

ch the motive power would be magnetic attraction, the attraction of a lodestone for a number of iron teeth arranged at equal distances on the periphery of a wheel. The device looked well on paper, beyond which stage it was not carried, perhaps for want of leisure, or more probably for want of the ne

he says: "In the long record of rascaldom from Peregrinus to Bamfylde Moore Carew, no single rascal stands forward with such magnificent effrontery, such majestic impudence, such astonishing success as Cagliostro." To say the lea

eel which, in a remarkable manner, moves continuously." He is writing from Southern Italy to his friend Siger (Syger, Sygerus), at home in Picardy; and that this friend may the better comprehend the mechanism of the wheel, he proceeds to describe in a systematic man

known to you in an unpolished narrative the undoubted though hidden virtue of the lodestone, concerning which philosophers, up to the present

g.

Needle of Petrus Pe

that whoever wishes to experiment should be acquainted with the nature of things; he must also be sk

f the magnetic work accomplished by the author and, at the same time, will se

RT

urpose of