ecies at
all.

{68}

OF GILBERT'S DE MAGNETE.

De Magnete magneticisque corporibus, et de magno magnete tellure. By
William Gilbert. London, 1600, folio.--There is a second edition; and a
third, according to Watt.[91]

Of the great work on the magnet there is no need to speak, though it was a
paradox in its day. The posthumous work of Gilbert, "De Mundo nostro
sublunari philosophia nova" (Amsterdam, 1651, 4to)[92] is, as the title
indicates, confined to the physics of the globe and its atmosphere. It has
never excited attention: I should hope it would be examined with our
present lights.

OF GIOVANNI BATISTA PORTA.

Elementorum Curvilineorium Libri tres. By John Baptista Porta. Rome,
1610, 4to.[93]

This is a ridiculous attempt, which defies description, except that it is
all about lunules. Porta was a voluminous writer. His printer announces
fourteen works printed, and four to come, besides thirteen plays printed,
and eleven waiting. His name is, and will be, current in treatises on
physics for more reasons than one.

{69}

CATALDI ON THE QUADRATURE.

Trattato della quadratura del cerchio. Di Pietro Antonio Cataldi.
Bologna, 1612, folio.[94]

Rheticus,[95] Vieta, and Cataldi are the three untiring computers of
Germany, France, and Italy; Napier in Scotland, and Briggs[96] in England,
come just after them. This work claims a place as beginning with the
quadrature of Pellegrino Borello[97] of Reggio, who will have the circle to
be exactly 3 diameters and 69/484 of a diameter. Cataldi, taking Van
Ceulen's approximation, works hard at the finding of integers which nearly
represent the ratio. He had not then the _continued fraction_, a mode of
representation which he gave the next year in his work on the square root.
He has but twenty of Van Ceulen's thirty places, which he takes from
Clavius[98]: and any one might be puzzled to know whence the Italians got
the result; Van Ceulen, in 1612, not having been translated from Dutch. But
Clavius names his comrade Gruenberger, and attributes the approximation to
them {70} jointly; "Lud. a Collen et Chr. Gruenbergerus[99] invenerunt,"
which he had no right to do, unless, to his private knowledge, Gruenberger
had verified Van Ceulen. And Gruenberger only handed over twenty of the
places. But here is one instance, out of many, of the polyglot character of
the Jesuit body, and its advantages in literature.

OF LANSBERGIUS.