The comment in the code at the bottom of the page looks wrong.

package bobsrocket
package fleets
class Fleet {
	// Doesn't compile! Ship is not in scope.
	def addShip() { new Ship }
}

It should read (like in Listing 13.4):
	// No need to say bobsrockets.Ship

Minor errata.

Second to last paragraph.

"the distance variable in class LegOfJourney in Listing 13.12" should
read "the distance value ..."

distance is a val in Listing 13.12.

"..the Rocket class above can access.."

Unfortunately, due to layout, the Rocket class in Listing 13.13 is on the
following page.

Suggestions: "the Rocket class below"
"the Rocket class in Listing 13.13"

Minor errata; typo/grammar.

Last paragraph.

"that are the located in the directory" should read 
"that are located in the directory"