To bring the boat up into the wind and reef a sail, lower the sail partially. First lash the cringle on the luff or forward edge of the sail, then stretch the foot of the sail taut with the after cringle and secure it. Roll the sail neatly and tie all the reef points with a square knot and haul the sail taut again. If reefiing has been delayed too long, it may be necessary to lower the sail entirely before reefing. If sailing in a river or near shore, the safer plan when reefing is to run the bow of the boat on the bank before attempting to reef. Always stand to the wind-ward of a sail when reefing.

To be always on the safe side, never belay the sheet. If desired, one turn may be taken about a cleat, holding the end so as to ease off quickly when necessary.

A good sailor will bring the boat up into the wind rather than ease off the sheet when struck by a puff of wind, but in sudden squalls both manoeuvres may be necessary.

Remember that your boat is not liable to capsize if the sheet is free so as to permit the sail to move in a direction parallel to the wind.

In small boats the safest plan is to take the boat promptly towards the nearest land in case of sudden storms approaching. Don't wait for them to strike before seeking safety and, when preparing for a storm, all persons in the boat except the helmsman, should sit amidshsips on the bottom of the boat and stay there. Always have an eye on the wind, watching for the approach of sudden puffs which might cause trouble.

Do not attempt to tack when a big wave is coming on the weather bow, and do not forget to shift your seat to the windard of the tiller at every tack.

If sailing close to the wind in a sea and an ugly, breaking sea is coming, safety lies only in putting the helm down and luffing right into the wave so as to take it end on, or nearly so, and as the wave passes, put the helm up and fill the sails so as to avoid losing headway.

Table of specfic gravities:

Aluminum

2.68

Lead, cast

11.35

Antimony, cast

6.71

Phosphorus

1.82

Bismuth, cast

9.82

Platinum, rolled

22.07

Brass

8.38

Pyrites, iron

5

Coal, compact

1.32

Quartz

2.65

Copper, drawn,

8.88

Silver, cast

10.47

Copper, cast

8.79

Sodium

0.97

Diamond

3.52

Sulphur, native

2.03

Gold, stamped

19.36

Tin, cast

7.29

Gold, cast

19.26

Zinc

6.86

Graphite

2.30

Sulphuric acid

1.85

Iron, wrought

7.79

Mercury

1.52

Iron, cast

7.21

Nitric acid

1.42

Before water can become steam the upward pressure of its vapor must overcome the downward pressure of the atmosphere; hence it follows that the boiling point of water is conditioned by the atmospheric pressure. Water bo"ils at a much lower temperature on mountain tops, where the pressure is comparatively small, than in the valleys.