A Method for Determining the Geographical Longitude of Places, from the Appearance of the Common Meteors, Called Falling Stars, Proposed by George Lynn, Esq; of Southwick, Northampton-Shire, in a Letter to Dr. Jurin, R. S. & Coll. Med. Soc.

to resemble a Person greatly hypochondriac. I still continued to him the Camphire, and the other alterative Medicines, for some Time, but in a much smaller Dose than what I gave him in his Illness: So in Nine Weeks he was perfectly cur'd, and continues in good Health. This, Sir, is the Substance of what I remember of the preceding Case, wherein I lay'd the whole Stress of the Cure on Camphire. I am, &c. V. A Method for determining the Geographical Longitude of Places, from the Appearance of the common Meteors, called Falling Stars, proposed by George Lynn, Esq; of Southwick, Northamptonshire, in a Letter to Dr. Jurin, R. S. & Coll. Med. Soc. S I R, Upon perusing, lately, the Account which the very ingenious Dr. Halley has given in the Transactions, No. 360, of that extraordinary Meteor which appear'd all over England, 19th of March, 1715. I observe One very great Use he suggests might be made of those momentaneous Phænomena, in determining the Geographical Longitude of Places, if we could but have the least Notice of their appearing, &c. I cannot but think, that some other Meteors which are very frequent, tho' little taken Notice of, might serve very well for the same Purpose. I mean those which are vulgarly call'd Stars shooting, or falling, being a Sort of natural Sky-rockets discharg'd at a very great Height, Height, as I cannot but imagine from this Circumstance, that they never appear, any of them, according to the best of my Observation, where the Sky is cloudy; and therefore, in all Probability, their Explosion is in the Regions far above the Clouds, and they themselves of the same Nature with (tho' perhaps less, and much lower than) that great Meteor above-mention'd, whose Height Dr. Halley computes to have been above 60 Geographical Miles, viz. much above the ('till then) reputed Limits of our Atmosphere. But supposing these I mention to be discharged only at 20 or 30 Miles high, they may be seen by different Observers at the same Moment of absolute Time, in very distant Places from one another, which is the Thing required: For, if in any Two Places, as the Doctor takes Notice, any Two Observers, by Help of Pendulum Clocks duly corrected by celestial Observations, do exactly note at what Hour, Minute, and Second, such a Meteor is discharged, the Difference of those Times will be the Difference of Longitude of the Two Places; nor does it require so much as the Use of a Telescope, as in the Methods hitherto put in Practice for that Purpose. Now these natural Rockets I have found to be very frequent in every Star-light Night; but especially after a stormy Day, or in a stormy Night. If, therefore, Persons who are prepared, as above, to be exact in their Time, and also have a moderate Knowledge of the several Constellations, so as to describe the Track of any of those Meteors amongst the Stars, would but bestow any determinate Hour to be agreed amongst them, as for Instance, from 8 to 9 each such Night, to watch and observe those Explosions, noting down immediately the Time and Track of them, it would be easy to determine, termine, upon comparing their Observations, which of those Explosions each of them see at the same Time; and thereby the Difference in Longitude of those Places would be exactly had, as above. It would, however, be worth the While, this Way, to try whether such common Meteors are discharged, at any considerable Height above the Clouds, and how far, and whether they differ much from one another in their Heights. But these Speculations I leave, Sir, to your better Judgment, either to improve the Hint, if it deserves it, or if not, entirely to suppress it; and in either Case remain Yours, &c. VI. An Attempt made before the Royal Society, to shew how Damps, or foul Air, may be drawn out of any Sort of Mines, &c. by an Engine contriv'd by the Reverend J. T. Desaguliers, L. L. D. and F. R. S. The Engine represented by the Model, consists of a Triple Crank working 3 Pumps, which both suck and force Air, by Means of 3 Regulators, and are alternately apply'd to drive Air into, or draw it from any Place assign'd, thro' square wooden Trunks; which being made of flit Deal, and 10 Inches wide in the Inside, are easily portable, and join'd to one another without any Trouble. Experiment I. I fill'd a tall cylindrick Glass with the Steams of a burning Candle and burning Brimstone Matches, in such Manner that a lighted Candle