THE LETTER OF
PETRUS
PEREGRINUS
ON THE MAGNET, A.D. 1269
TRANSLATED BY
BROTHER ARNOLD, M.Sc.
PRINCIPAL OF LA SALLE INSTITUTE, TROY
WITH
INTRODUCTORY NOTICE
BY
BROTHER POTAMIAN, D.Sc.
PROFESSOR OF PHYSICS IN MANHATTAN
COLLEGE, NEW YORK
NEW YORK
McGRAW PUBLISHING COMPANY
MCMIV
Copyright, 1904, by
McGraw Publishing Company
INTRODUCTORY
The magnetic lore of classic antiquity wasscanty indeed, being limited to the attractionwhich the lodestone manifestsfor iron. Lucretius (99-55 B. C.), however, inhis poetical dissertation on the magnet, containedin De Rerum Natura, Book VI.[1] recognizes magneticrepulsion, magnetic induction, and to someextent the magnetic field with its lines of force,for in verse 1040 he writes:
Oft from the magnet, too, the steel recedes,
Repelled by turns and re-attracted close.
And in verse 1085:
Its viewless, potent virtues men surprise;
Its strange effects, they view with wond’ring eyes
When without aid of hinges, links or springs
A pendant chain we hold of steely rings
Dropt from the stone—the stone the binding source—
Ring cleaves to ring and owns magnetic force:
Those held above, the ones below maintain,
Circle ’neath circle downward draws in vain
Whilst free in air disports the oscillating chain.
The poet Claudian (365-408 A. D.) wrote ashort idyll on the attractive virtue of the lodestoneand its symbolism; St. Augustine (354-430),in his work De Civitate Dei, records thefact that a lodestone, held under a silver plate,draws after it a scrap of iron lying on the plate.Abbot Neckam, the Augustinian (1157-1217),distinguishes between the properties of the twoends of the lodestone, and gives in his De Utensilibus,what is perhaps the earliest reference tothe mariner’s compass that we have. AlbertusMagnus, the Dominican (1193-1280), in histreatise, De Mineralibus, enumerates different kindsof natural magnets and states some of the propertiescommonly attributed to them; the minstrel,Guyot de Provins, in a famous satirical poem,written about 1208, refers to the directive qualityixof the lodestone and its use in navigation, asdo also Cardinal de Vitry in his Historia Orientalis(1215-1220); Brunetto Latini, poet, oratorand philosopher, in his Trésor des Sciences, a veritablelibrary, written in Paris in 1260; RaymondLully, the Enlightened Doctor, in histreatise, De Contemplatione, begun in 1272, andGuido Guinicelli, the poet-priest of Bologna,who died in 1276.
The authors of these learned works were toobusy with the pen to find time to devote to theclose and prolonged study of natural phenomenanecessary for fruitful discovery, and so had to contentthemselves with recording and discussing intheir tomes the scientific knowledge of their age