The key word in this passage is "pleasure" which indicates that Columbus's tone of voice is one of excitement and unbounded delight, due to "discovering" the many islands during his first voyage in 1492 which he was convinced held untold treasures like gold and silver which would help fill the coffers of the Spanish monarchy, thus guaranteeing that Spain would rule and dominate not only the lands but also the people by converting them to Christianity. In contrast, Columbus's second letter addressed to the King and Queen of Spain sometime in 1493 is much more to the point and lacks any and all references to Columbus's highly subjective tone of voice regarding the lands and the possible riches they might hold. For example, Columbus mentions that the island of Espanola contains land "safer and better for farming and trading," a sign that Columbus is now only focusing his tone on the overall economic advantages of the "New World" related to creating farms and towns rather than gold and silver. Also, Columbus points out that no one "shall have liberty to collect...

With this, it is clear that Columbus's tone and diction has changed radically, beginning with great optimism and "pleasure" to almost outright indifference.
References

Christopher Columbus." (2004). New Advent Catholic Encyclopedia. Internet. Retrieved at http://www.newadvent.org/cathen/04140a.htm.

Doak, Robin S. (2005). Christopher Columbus: Explorer of the New World. New York: Compass Point Books, Inc.

Ife, B.W. (2005). "Introduction to the Letters from America." Internet. Retrieved at http://www.ems.kcl.ac.uk/content/pub/b002.html.