decide upon nothing definite at this time, we shall leave a record of the truth for a future time." Colon says:]
First, inasmuch as the division of the sphere, which is an unknown quantity, is to be determined, we must determine and verify its size. This must be done by one of two methods, namely, by measuring the entire globe or body to be divided; or by ascertaining exactly the proportional relation between one portion of it and the corresponding portion of another body, whose size is known to us, as for instance the heavens, which learned men have divided into three hundred and sixty parts or degrees.
As to the first method of measuring the earth, besides being very difficult, it becomes also arbitrary unless measurements were always made by line. Much uncertainty is occasioned by this method, because, as we hear and say continually such and such leagues are very long, while others speak of them as small, each one judging according to his own opinion, and taking into consideration the time and rapidity it took him to walk them. On this account a much greater difference will result when the said leagues are measured by sea, for there are many more obstacles that alter or impede the correct calculation of them, such as, for instance, currents, tides, the ship's loss of speed, because of its meeting with strong head winds, or because of heavy seas coming athwart the bows, or from other directions. In addition to all these one may be deceived by the ship's burden and bulk; or by reason of the ship's bottom being cleaner or dirtier at one time than another; or whether it is towed or sailing alone; or whether it carries new or old sails and whether they are of good or ill pattern,
