This discovery was followed by that of the calculus of partial differences, the first trials of which were published in his Reflexion sur la cause generale des vents (1747).
The springs, geysers and steam vents are scattered over it in the most irregular fashion.
A dry and warm wind comes down from the snowy Elburz to Gilan in December and January, and much resembles the fhn of the Alps (Dr Tholozan, Sur les vents du Nord de la Perse et sur le foehn du Guilan, Corn pies rendus, Acad.
But Brunhild is ill content; though she saw Siegfried do homage to Gunther at Isenstein she is not convinced, and believes that Siegfried should have been her husband; and on the bridal night she vents her ill humour on the hapless Gunther by tying him up in a knot and hanging him on the wall.
These four great poems, one in sublimity of spirit and in supremacy of style, were succeeded next year by a fourfold gift of even greater price, Les Quatre Vents de l'esprit: the first book, that of satire, is as full of fiery truth and radiant reason as any of his previous work in that passionate and awful kind; the second or dramatic book is as full of fresh life and living nature, of tragic humour and of mortal pathos, as any other work of the one great modern dramatist's; the third or lyric book would suffice to reveal its author as incomparably and immeasurably the greatest poet of his age, and one great among the greatest of all time; the fourth or epic book is the sublimest and most terrible of historic poems - a visionary pageant of French history from the reign and the revelries of Henry IV.
It has been suggested that these spurs represent the sites of vents or fissures of eruption.
The lavas are usually porphyrites, which occur in sheets, with intercalated bands of volcanic tuff that are sometimes strongly felsitic. One of the vents by which such materials were ejected occurs in the Braid Hills on the south side of Edinburgh.
The actual vents which were the sites of the small volcanoes still remain distinct, and the erupted lavas form high ground in the middle of Ayrshire.