Red Sail, 18th reader, contains thirty new words. The story material flows more freely as there are over two hundred words the child can now recognize. The type size has been reduced thereby increasing words per page. Red Sail introduces important trigraphs — “all,” “est,” and “end.” These small parts of words make it possible for a child to recognize at least one hundred words or more. The concept of the compass is introduced. To measure the speed of a sailing vessel before the discovery of electronics, a log line was tossed into the ocean. Every 47 feet and 3 inches a knot was tied. The speed of boats, ships and airplanes is measured in knots per hour today as in ancient times.