A new discovery for finding the longitude

by William Hobbs

Note, That in this Movement, the Time is Regulated or Conformed to the Motion: Whereas in former Movements, the Motion is Regulated or Conformed to the Time. And this ought to be well understood, before you can rightly comprehend what is herein contained.

Now that this Movement, or Discovery, does not only differ from, but also far exceed, any that has hitherto been proposed; is evident in this (viz.) That if any former Movement whatsoever be Timed here, as usual, Before it is carried to Sea, (tho’ never so exactly) yet the change of Climate, &c. will so affect it, as to make it go False: And if you fit it there, then ’twill be also False when brought hither: But if by this Movement, and the foregoing Rules, the said Numbers be found After it is returned from such a Voyage; all the said Defects or Contingencies will be Æquated by the said Numbers only. So that it will be the same in use, as if no such Accidents did attend it at all. And this Assertion must, and will be granted, by every one that does fully comprehend the Nature and Use thereof. For altho’ this Horologe has no certain Hours or Time pre-assigned to it; yet it hath nevertheless, greater or lesser Numbers Æquated to the Variableness of Motion or Time, (viz.) If fitted to be used here in England, then it hath (or may have) one sort of Numbers (or Time) for finding the Hour and Minute, in the Summer Season; another for Winter; and a third for the Spring and Fall; one when it lyeth undisturbed in one and the same place; another (if you please) when carry’d always in a Rattling Coach. And on the other hand, if you carry it to Sea, then it has one for the Torrid, one for the Frigid, and a third for the Temperate Zones, &c. And yet still but one and the same Horologe, and but one and the same Indexes. So that all manner of Natural Vicissitudes or Contingencies whatsoever, may be Regulated or Æquated in and by the said Numbers; and consequently, the true Hour and Minute of the Day, where it is first set going, may be hereby as effectually found, as if no such Impediments did at any time or place attend it, as aforesaid.

And as for what may be suggested in relation to the Inequality between the Spring and Fusie, if any should be, it will be compensated, in that there are five or six Windings up of them, to one Revolution in the Horologe. So that there is nothing wanting to compleat this Discovery, but to put it into Practice: And seeing the Charge and Trouble is very Inconsiderable; and the Legislature by Act of Parliament, hath been graciously pleased to Incourage hereunto, it is thought expedient to make this publick Proposal, viz.

That if any one Person is willing to Engage in this so Noble an Enterprize, he will be readily received as a Partner, on such Conditions as may be Reasonably Concerted therein.

You may hear of the Author at Mr. Burleigh’s in Amen-Corner, London.

MEMORANDUM.

1. All Departures must be reckon’d from London, if the Movement was there Set going.

2. That wheresoever they are Set going, there must be a large and exact Meridian Line prepared by a Perpendicular, set up in an Horizontal Circle, as is Mathematically taught, &c.

3. That an Equal time be spent in Winding it up, as near as possible; for which no time need be allowed, if Equated for 10 or 12 Months; because the time required will be the same for the same time, and greater for a greater, &c.