An Accompt of Some Books

Miscelaneorum capiubi &c., quâratione flexus contrarii curvarum ex Tangentibus inveniantur, ostendi. Eadem ratione reperitur quoque curvâdes ῥότης, ut vocat Pappus, & multa alia; qua si explicare vellem, liber mihi scribendus esset. Nam & in Physico-mathematicis Usus quoque hujus Regula opinione major est: Licet enim falsum sit Axioma, Naturam agere per lineam brevissimam; verissimum tamen est, Viam sequi determinatam, &c., ubi nullam inventit, agere doceas. De quo aliis plura, si tanti Tibi visum fuerit: jam enim epistola modum excessit, ac vereor, ne, dum obscuritatem vitare satago, in prolixitatem incidierim. Addo tantum, me Regula mea Demonstrationem * habere facilem, & qua solis constet Lemmatibus, quod mirum Tibi fortasse videbitur. Valet. Dabam Leodii d. 17. Januar. CIDIDCLXXIII. * Non dubitamus, quin rogau nostro Illustri & Candidus hic Author Demonstrationem hic indigitatam Nobis etiam brevi sit communicaturus. An Accompt of some Books. I. A Discourse concerning the Origin and Properties of WIND, &c. By R. Bohun Fellow of N. Coll. in Oxon. Printed at Oxford 1671. in 8°. The Industrious Author of this Discourse, having consider'd with himself, how little Progress had been made, as in general, in the History of Nature, so, in particular, concerning the History of Winds, till our Voyages to the East and West-Indies, and the great advancement of Navigation in this and the precedent Age, furnish't us with so many new Discoveries and Improvements in all Natural knowledge, especially in the Motions of the Winds and Seas, that we must acknowledge the Insufficiency of the Theories received from the Schools of the Antients; having, I say, considered this, and withall met with frequent opportunities of conversing with the most Experienced of our Sea-Captains, giving him good information of the Course of the Trade-winds, the Indian Monzoons, the several sorts of Breezes in the African and American Climates, Hurricanes, and other tempestuous Winds: Endeavoureth in this Discourse to give a fuller Accompt of this Subject than former Writers have done, proceeding therein, as he assureth the Reader, with great caution, in seldom making use of any Account of Voyagers, but when several Relations did agree in the same Particulars, or when he found the Relators to be persons of unsuspected Integrity: Occasionally adding diverse Philosophical Reflections, in which he adhereth not to any one Hypothesis, but maketh use of several, as they to him seem to serve best for the Explication of the present Phanomena. 1. Then, he discourseth of the Opinions of the Antients, and compareth with them the Placits of the Moderns, considering Wind to be a Sensible Motion or Protrusion of the Air. 2. He examins the Local Origins of Wind, and compriseth them under Three general Heads; as generated 1. In the Lower Region, by the Dilatation of Vapours or Air; by a surcharge of the Atmosphere; by the Pressure of Clouds, or the Elastic power of the Air. 2. From the Earth or Seas, as from Submarine or Subterranean Eruptions; where he gives divers Historical Instances of Winds breaking from under the Earth or Sea, and particularly of the famous Mascarets in the River of Dordogne, and the sudden Tumors in the Lake of Geneva. 3. By Descent from the Middle Region; where he makes their Gravity to be the Cause of their Descent, not their Repulse from the Antiperistasis of Contraries. 3. He ventures to explicate the Fluxes and Refluxes of the Air and Winds, and their Motions to several Quarters, and that, by the most Violent Impulse made that way where they find the medium most yielding, and fittest to propagate their motions. 4. He gives the reason, why some winds blow with greater violence than others; observing, that those which are nearest their Local Origins blow hardest, especially such as are re-inform'd by other auxiliary vapors as they pass. 5. He considers the Essential Attribute of Winds to be their Transverse Motion, and inquires into the various Causes of the same; discoursing withall of the other Secondary Affections of Winds; as their Undulation, Repercussion from Promontories, Opposition, &c., Where he endeavors endeavors to explain, how it comes to pass, that one Wind blows on the Top of a Mountain, and a quite contrary in the Valley below; and why in the main Sea, Winds keep the same Quarter a long time, but near mountainous Islands or Shoars they whistle up and down, and shift from one point of the Compass to another; Observing also, that sometimes Contrary winds do encounter together, and that by their ballancing one another a Calme ensueth. 6. He treats of the Matter of Winds, their Limits and Extent, and the most Windy Seasons; giving an account, why they blow more in Spring and Autumn, than at other times. 7. He proceeds to the History of the General or Tradewind, alleging the Causes why it blows constantly from the Easterly points, and imitates the Course of the Sun: Instructing us withall, where it is to be expected on this side of the Tropique; as also of the Variation thereof in several Longitudes, and the Cause of the blowing of the Westerly winds without the Tropiques. 8. He treats of Provincial winds, such as wander not far from their native fountains, and terminate in those Regions that gave them birth. 9. He gives the History of the Land and Sea-Breezes; when they come in, or cease, in the Straights, on the Coasts of Guiney, and the East and West-Indies; and what Accidents hasten or retard their approach. 10. He discourses of the Anniversary Winds; their several species, and particularly those in the way to the East Indies, called the Monsoons: How many months they continue the same Course on the Coast of Afrique and India; together with the Changing and Breaking up of the Monsoons, and the danger there is then at Sea when they do so. 11. He examines the Qualities of Winds, derived from their Constituent Parts, or the Medium they pass through. Where he descends to the Consideration of the Properties of Easterly, Southerly, Westerly and North-winds; inserting divers divers remarquable Observations concerning them, and giving a Caution withall, to be used in Judging of the Qualities of Winds. Here also come in his remarques concerning Hot and Cold Winds, and the examination of their Causes; concluding this Head not only with observing some Unusual Qualities of Wind, and the different odd Impressions they make upon other Bodies; but also delivering some proposals, for a more accurate Discovery of the Nature and Qualities of Winds, in relation to Navigation, Architecture, and several Trades and Mechanical Arts. 12. He inquires into the Prognosticks of Winds, from the different Appearances of the Celestial Bodies, from the Roaring of the Sea, the Refounding of Echo's, the peculiar Actions or Passions of some Living creatures, &c. 13. He subjoins an Historical account concerning Whirlwinds in general, and Tornados, Hurricanes, and other Tempestuous Winds; concerning which he delivers several uncommon and very remarkable Relations. As to the whole matter, He is well aware, that it Will be hard to lay down any perfect Theory of Winds, in regard that the great Inequalities in the Superficies of the Earth; the several Obstacles and Repercussions from mountains; the different Situations of the places and Mediums in which they blow; the Distance of those Countries from the Poles of the World; their Respects to the Course of the Sun, whether they comply with, or resist, the Natural Motion of the Air from East to West, &c; have many intricate and nice speculations, not easy to be stated. II. Deux Machines propres à faire les Quadrans, avec tres-grande facilité; par le P. Ignace Gaston Pardies S. J. À Paris 1673, in 12°. The Learned Author, Professor of the Mathematiques in the Parisian College of Clermont, having found, that the difficulty, met with in the Practick of Dyalling, and in In that tedious train of divers operations that are to be made in following the common method, generally taketh away the pleasure that would be in the exercise of a work that else is so curious and useful; is of opinion, that those inventions will be much esteem'd, that shall make this practise easie. And in order thereto, he describes and explains in this Tract two Engines, which to him seem very proper for that purpose; forasmuch as he finds, that by the means of them a man may learn in less than an hour the way of making all sorts of Dials, and may practise what he has learnt, as 'twere by playing, drawing them upon Walls and in his Chamber with the greatest facility. He adds, that we are not to imagine, that the Use of these Instruments is but such a Mechanical Operation, where a man works blind-fold, not knowing what he doth: And he declares, that, as to Operation, those Practices that are simplest and surest are to be held the best and the most geometrical; and he is of opinion, that scarce anything can be done with less trouble or with more certainty than by means of these Machines. But then, if the question be, to learn the Theory of Dyalling, he believes not, that it can be better done than by the Use of these very Engines; wherein he affirms that the Learner may easily be made to understand the Reason of all the Operations, the Respect of the Horary lines to the Course of the Sun, the Sections which the Arches of the Signs do make, and, in a word, the whole Science Gnomonique. The Description and Explication of these Instruments doth so much depend upon the view of the Schemes, employed therein, that it cannot be well made without them: Which maketh us refer the Curious Reader to the Tract itself, now come over, wherein the necessary Schemes are annexed to the Discourse.