FERRARIS. 00 memoir by Ferraris, On the Differenct of Phase u, Currents, on the l.n<j oj Induction and on the WasU oj Energy in Transformers, was published in 1887, and treats thoroughly the subject in its many bearings. In 1893 he published a theory of the single-phase alternating motor and toward the end of his life he was engaged in devising apparatus to transform alternating currents. '1 he part played by Professor Ferraris in the lopment of alternating currents cannot be overestimated, and his works are considered standards. FER'RATES (from Lat. ferrum, iron). Salts of the hypothetical ferric acid, including chiefly the barium, potassium, and sodium ferrates. See Ibon. FERREIRA, fgr-ra'4-ra, Antonio (1.328-69). One of the classic poets of Portugal. He was born at Lisbon, and was educated at Coimbra, where he occupied himself especially with the study of the Italian and Latin authors, and where he remained for some years as professor of jurisprudence. Finally he obtained an im- portant civil appointment at the Court of Lisbon, where he resided until his death from the plague. Of all the followers of Sa de Miranda, he was most successful in imitating the Italian and Latin forms of verse, perfecting the elegiac and epistolary styles already attempted by Miranda, and transplanting into Portuguese literature the epithalamium, the epigram, and the ode. His Ines do Castro is the earliest Portuguese tragedy, and, with the exception of Trissino's Sophonisba, the earliest in Europe, after the revival of let- ters. His comedies, Bristo and Cioso, both early works, are full of interest to the student of literarv history. The second was translated into English by Musgrave (1835). Consult: Castilho, Antonio Ferreira (Rio, 1 S 7 ."> I , and Braga, His- toria dos Quinhen tistas (Oporto, 1871). FERREIRA, Thomas A. R. See BinEiRO- Ferreira, Thomas Antonio. FERREIRO, fer'ra-S're (Port., Bmith; from its cry). A Brazilian tree-frog or 'escuerzo' {Hyla faber), 3% inches in length, remarkable for its breeding habits. In February these ting- resort In muddy pools, where mating takes place, and the females form from the mud beneath the water circular walls, which rise two to four inches above the surface and inclose pools a foot or so in diameter, in which fin tre laid, and where the tadpoles remain until well grown. These circular nurseries are constructed with much care by the females alone, each meanwhile carrying her male mate upon her back, waiting to fertilize her eggs. The work i- dune at night. Consul! Goeldi, Proceedings Zoological Society of London, pp. '.hi 97 i 1895). FER'REL. W'ijuam (1817-91). An Ameri- can meteorologist, lie was bom in Bedford County, Pa., and early removed to Virginia. lie .i educated a1 Mar-hall College (Mercers- burg, Pa.), and at Bethany College (Virginia), I mm I lie bit ler in-l it ill inn ill I S I I. Hi- meteorological researches won attention, both in America ami Europe, and it may be said that many of the Fundamental propositions of meteor ■x were laid down by him. He was asSOCiat eii i • i in i he computal ion - of 1 he auti- cil Almanac until isr>7. when he was appointed tn the I Fnited i i nd < leodet ic Survey. From is82 to 18SU he was stationed at Wash- 2 FERRETING. ington, as an assistant in the Signal-Service Bureau, where he continued his independent in- vestigations. His maxima and minima tide-pre- dicting machine has been for many years in gen- eral use in the Government coast surveys. Among his literary productions may be mentioned: "The Problem of the Tides," in Gould's Astronomical Journal (1856); Converging Series; Ratio of Diameter and Circumference of t'ircles (1871); Tidal Researches (1874); Meteorological Re- searches (1S75-81) : Influence of the Earth's Ro- tation on the Motion of Bodies; Motions of Fluids and Solids; Tidal Action. FERRET (Fr. furct. It. furetto, from ML. fu- retus, diminutive faro, ferret, from Lat. fur, thief ; apparently connected by popular etymology with Lat. fern, wild beast). (1) An animal of the weasel family (Mustelida?) . so nearly allied to the polecat (Putorius faetidus) that many re- gard it a- a mere domesticated albinotic variety. Others regard it as a distinct species, which they call Putorius furo. It is of rather smaller size, the head and body being about 14 inches long, the tail 5% inches, the muzzle somewhat longer and more pointed, the head rather narrower; the color is very different, being yellowish, with more or less of white in some parts, due to two kinds of hair, the longer partly white, the short- er yellow. The eyes are pink. It is, however, much more susceptible to cold than the polecat, and requires careful protection from it in cli- mates where the polecat is a hardy native. It was imported into Europe from Africa, and was used in Rome as a mouser. Attention to warmth and cleanliness is essential to the health of fer- rets. They arc capable only of partial domesti- cation, acquiring a kind of familiarity with man, and submitting with perfect quietness to his handling, but apparently never forming any very decided attachment: and they never cease to be dangerous if not carefully watched, especially where infants are within their reach. If allowed any measure of freedom they are ready to attack poultry, and kill far more than they can devour, merely sucking the blood. They generally breed twice a year, each bi'ood consisting of six or nine. The female sometimes devours her young, in which case another brood is speedily produced. Consult Everitt, Ferrets: Their Management (London, 1897). See Plate of Fub-Beamng Animals. 12) In the Western United States, a weasel of the plains, the black-footed ferret [Putorius ni- gripes), which lives in the prairie-dog 'towns,' feeding on those animals. It is pale brown, with the feet, tip of tail, and a bar across the face black. It i- about two feet long. FERRETING. The ferret i< bred and trained in captivity. Rabbits have the same instinctive apprehension of coming danger from the presence of tlie ferret that birds in general have of the 1 flying hawk, and sportsmen take advantage of this characteristic. They breed the ferret and place it sometimes free sometimes on a string, ami sometimes muzzled — in the burrows or un- derground run- in :i rabbit warren, from which Hs presence causes the rabbits to -curry off into I he open fields. The young ferrets are taught by being entered in the first instance with their mother, who -"nil initiates them into working n burrow. Ferrets are equally efficacious in starting rats from their underground homes, or
