d about. And considering with themselves, how much
they may increase their _Philosophical_ stock by the advantage, which
_England_ injoyes of making Voyages into all parts of the World, they
formerly appointed that Eminent Mathematician and Philosopher Master
_Rooke_, one of their Fellowes, and _Geometry_ Professor of _Gresham
Colledge_ (now deceased to the great detriment of the Common-wealth of
Learning) to think upon and set down some _Directions_ for _Sea-men_ going
into the _East_ & _West-Indies_, the better to capacitate them for making
such observations abroad, as may be pertinent and suitable for their
purpose; of which the said Sea-men should be desired to keep an exact
_Diary_, delivering at their return a fair Copy thereof to the _Lord High
Admiral_ of _England_, his Royal Highness the _Duke_ of _York_, and another
to _Trinity-house_ to be perused by the _R. Society_. Which _Catalogue_ of
_Directions_ having been drawn up accordingly by the said Mr. _Rook_, and
by him presented to those, who appointed him to expedite such an one, it
was thought not to be unseasonable at this time to make it publique, the
more conveniently to furnish Navigators with Copies thereof. They are such,
as follow;

1. To observe the Declination of the _Compass_, or its Variation from the
_Meridian_ of the place, frequently; marking withal, the _Latitude_ and
_Longitude_ of the place, wherever such Observation is made, as exactly as
may be, and setting down the _Method_, by which they made them.

2. To carry _Dipping Needles_ with them, and observe the Inclination of the
Needle in like manner.

3. To remark carefully the Ebbings and Flowings of the Sea, in as many
places as they can, together with all the Accidents, {142} Ordinary and
Extraordinary, of the Tides; as, their precise time of Ebbing and Flowing
in Rivers, at _Promontories_ or _Capes_; which way their Current runs, what
Perpendicular distance there is between the highest Tide and lowest Ebb,
during the Spring-Tides and Neap-Tides; what day of the _Moons_ age, and at
times of the year, the highest and lowest Tides fall out: And all other
considerable Accidents, they can observe in the Tides, cheifly neer Ports,
and about Ilands, as in St. _Helena_'s Iland, and the three Rivers there,
at the _Bermodas_ &c.

4. To make Plotts and Draughts of prospect of Coasts, Promontories, Islands
and Ports, marking the Bearings and Distances, as neer as they can.

5. To sound and marke