that have _Minutes_ and _Seconds_, with _Checks_,
according to Mr. _Hugens's_ way.

And because if the Hole, by which the water is let into the Pump, be as
large as the Bore of the Pump it self, the weight that is raised by the
water, will rise and fall with an Undulalation, according to the inequality
of the Sea's Surface, 'twill therefore be fit, that the Hole, by which the
water enters, be less than half as bigg as the Bore of the Pump; any
inconvenience that may follow thereupon, as to the Periods and Stations of
the Floud and Ebb, not being considerable.

And to the end, that it may appear the better; what are the _particular_
Observations, desired to be made, near _Bristol_ or _Cheap-stow_ bridg, it
was thought not amiss, to set them down distinctly by themselves.

1. The degrees of the Rising and Falling of the water every quarter of an
hour (or as often as conveniently may be) from the Periods of the Tides and
Ebbs; to be observed night and day, for 2 or 3 months.

2. The degrees of the velocity of the Motion of the Water every quarter of
an hour for some whole Tides together; to be observed by a second
_Pendul_-watch: and a logg fastened to a line of some 50 fathoms, wound
about a wheel.

3. The exact measures of the Heights of every utmost High-water and
Low-water, from one Spring-tide to another, for some Months or rather
Years.

4. The exact Heights of Spring-tides and Spring-Ebbs for some Years
together.

5. The Position of the Wind at every observation of the Tides; and the
times of its Changes; and the degrees of its Strength.

6. The State of the Weather, as to Rain, Hail, Mist, Haziness, &c, and the
times of its Changes.

7. At the times of observation of the Tides, the height of the
_Thermometer_; the height of the _Baroscope_; the height of the
_Hygroscope_; the Age of the Moon, and her _Azimuths_; and her place in all
respects; And lastly the _Sun's_ place; all these to _minutes_.

And it would be convenient, to keep _Journal Tables_, for all these
Observations, each answering to its day of the Month.

For the _Apparatus_ of all these observations, there will be particularly
necessary.

A good _Pendulum_-watch.

A _Vane_ shewing _Azimuths_ to minute parts.

An _Intrument_ to measure the Strength of the Winde.

A large and good _needle_ shewing _Azimuths_ to degrees. {301}

_Thermometers_, _Barometers_, _Hygroscopes_.

These Observations being thought very considerable as well as