1

3

I fhall fay here, is, That I have try'd all my Experiments at Land, with defir'd Succefs, and as foon as the Bookfeller has paid me, I'll go to Sea; and if, after all, I fail in the Attempt, yet-Vobifcum certaffe juvabit. I am, Gentlemen,

Your most devoted, moft obedient,

and most humble Servant,

Jeremy Thacker, Philomath.

Well-wisher to the Twenty Thousand Pounds.

Advertisement concerning the Longitude.

I

This now well nigh towards half a Year, fince "my good Genius, and my Self, found out a Method for difcovering LONGITUDE, which I had publifh'd before, had it not been on Account of the Creatures of Trap and Discovery, who, (I had Reason to fear) would have run away with the Secret that Nature had confefs'd to ME, and "had refus'd to THEM, as otfen as they have afk'd her for it. But now, that Things are fo fettled, that no Body can rob me of the Benefit of my Invention, I publish this to defy all that can be "done by thofe of the Snearing and Grinning Kind, "in their proper Employment of Ridicule and Gri66 mace: And therefore I expect all my Readers to "be Merry or Angry, or Grave or' Serious, upon "this Occafion; but I muft (and indeed I dare)

fubmit myself to the Multitude, who, if I am "not mistaken, will declare me a Fool or Mad"man, with Pomp and Ceremony, for being fo po"fitive; and therefore I do, by Aftrological Cal"culation, prognofticate, that fome will defire 1

"Should

should be in the Wrong; others will have a Sufpiscion that I am in the Right; and the Ignorant "will not know whether I am Right or Wrong.

Jeremy Thacker.

'HAT if the greatest Part of the Pack have

WHA

a

moft Dog hit it off? Perhaps, from my comparing the Seekers after the Longitude, to a Pack of Hounds, fome arch Wags will fay, that if one or two Dogs run mad, it is ten to one but all the reft catch the Infection, and fo look upon him as a Mad-man; let 'em fneer on; for if I can but demonstrate myself to be in the Right, and all the reft in the Wrong, (as I am confident I can) their Laughing will be turn'd into Admiration; and when I receive the Reward, they'll fay, Who wou'd have thought it?

If I fhould follow the Example of the greatest Part of the Longitudinarians, that wrote after the firft Attempt, I fhould take Mr. Whiston and Mr. * Ditton in Hand, fhipwreck their Hulls, drown their Sounds in a Tempeft, lift up the Waves to intercept the Sight of their Fires, and break their General Peace; but Gratitude forbids: They fprung the Twenty Thousand Pounds, and I hope to get it, I ought to be civil to them. Then let Mr. D. reft affur'd, that I will neither meddle with his Longitude, nor his New Law of Fluids; and poor Mr. W. has been fo often handled as a Longitudinarian and a Latitudinarian, fo amaz'd at the Burfting of his Mortar, and one of his Shells, and fo frighten'd with the Fall of another unlighted one, that it would be as barbarous as ungrateful for me to infult over him.

E 3

him. No, I fhall always own him the Maker of my Fortune. I had no great Acquaintance, no Friends at Court; I could by no Means have procur'd an Act of Parliament for my Encouragement: My Engine was ready these three or four Years; fo I was glad when he ftirr'd. I lay ftill, well-knowing that he was beating the Bufh for me to catch the Hare.

Before Mr. Hobbs thinks of fending his SpringMovement to Sea, let him know how to make the Month of June in one Year, just as hot as the fame Month in another, and fo of every Day and Month in all Years; then his Inftrument will be equally haften'd and retarded at the fame Seafons; and then he may polifh his Pivots, and make an Etherial Oil that won't thicken and increase the Friction of his Watch.

Mr. Billy (after having acquainted us with feveral admirable and furprizing Phænomena of Nature, which he took for Conjuring, the first Time he faw them, but now dares venture to perform himfelf, (and by himself) very reasonably tells us, That fince the Phosphorus, Glass-Devils in Water, &c. which would, to a Stranger, feem to be actuated by Magic; to us that are wifer, appear to be the Effects of no other Arts, but Chymiftry and Legerdemain; his finding out the Longitude, after fo many have attempted it in vain, is a Thing no franger than it is true. His Movement is ftill behind the Curtain, but I'll think the beft of it; and Ifince he has vouuchfafed to tell us, That he will, by Means of a long Pendulum, have a steady Motion in an irregular one, I'll help them out, and affure him, that he will fucceed, if he will do one Thing more, and that is, prove Sir Ifaac Newton's first Law of Motion to be falfe.

-"I have little to fay to Mr. Br-e, the Corrector of the Moon's Motion; but if his Application of it be practicable for trying to find the Longitude, I'l turn him over to the Aftronomers, for the Exami nation of his Theory; and I would not be in his Cafe, if he fhould fall into the Hands of Dr. John Keil, who knows how to revenge the leaft Injury done to Dame Nature his Miftrefs, by the falfe Reports of bad Philofophers.

The Latitude, no doubt, may be exactly found by Signior Al-ri; but if he would difcover the Longitude by his Machine, he fhould defire his Workmen to make him a long Leaver, not to move, but to stop the Earth; or if Ptolemy has done that for him already, let him fhove up his Leaver, and stop the Primum Mobile: If he wants Help, Mr. K--th will lend him an Hand, and tell him what Star he fhall chufe for an Eastern'or a Western Pole. However, let not our Italian Gentleman be difcourag'd from giving us the Figure of his Engine; for he is not the firft Profeffor of Mathematics that has fallen fhort of the Longitude: And though I can't commend his Scheme, because I am his Rival in this Cafe, yet, if he'll try for the Philofopher's Stone, or fquare the Circle, I'll fub fcribe to it. And if my Friend K- th would have his Method effectual, let him take a Journey to the Moon, where he will be certain of his Longitude by his Obfervations of the impending Earth; he may find a fufficient Number of Ganza's among the Latitudinarians to carry him thither, and the Luna_ tick Attraction between the Moon on the one Hand and himself and the Ganza's on the other, will make his Voyage speedy.

Mr. J. H. Writer of the Effay, has such a fertile Brain at Invention, that I know not how to deal with him:

He'll raife Objections dark and nice,
And after folve 'em in a Trice.

And if I demolish one of his Movements, he'll pop upon me in a Moment with another. If I tell him, that the Mercury in his portable Barometer with the fpiral Bafon, will vibrate ten or twenty Inches by the very Shake of the Ship, because the common portable one, which is ten or twenty times lefs fenfible as to the Mercury's Rife and Fall, will, with the leaft Shake, vibrate half an Inch) he'll fubftitute Dr. Hook's Marine Barometer, and have me there again: But then (granting him his Theory of the Tides) he must confider that the Moon raifes a Tide in the Atmosphere, as well as the Ocean; and as he rifes from his Level with his Barometer in hand, where he expects the Liquor to defcend, he will find himself baulk'd, because the Height of the counterpofing Atmosphere, will not decrease in that Cafe, as it would do at Land.

But then the Pendulum in the Center of the Gravity of the Ship, muft it not always vibrate? That it will be in Motion all the while that the Ship goes, I readily grant; but then it must be in abfolute Motion; for if ever the Ship goes steady it will be at relative Reft; (that is, (in mechanical English) at Reft in Respect of the Things about it in the Ship) and therefore it will not move his Watch-Work. If he would have this Inftrument go, let him confult about it with the Inventors of a perpetual Motion; * and for his Time-keeper by a Vacuum, let him

He may hear of feveral at Birmingham or Sheffield.