Collado's explanation of how the various guns were invented is perhaps naive, but nevertheless interesting: "Although the main intent of the inventors of this machine [artillery] was to fire and offend the enemy from both near and afar, since this offense must be in diverse ways it so happened that they formed various classes in this manner: they came to realize that men were not satisfied with the _espingardas_ [small Moorish cannon], and for this reason the musket was made; and likewise the _esmeril_ and the falconet. And although these fired longer shots, they made the demisaker. To remedy a defect of that, the sakers were made, and the demiculverins and culverins. While they were deemed sufficient for making a long shot and striking the enemy from afar, they were of little use as battering guns because they fire a small ball. So they determined to found a second kind of piece, wherewith, firing balls of much greater weight, they might realize their intention. But discovering likewise that this second kind of piece was too powerful, heavy and costly for batteries and for defense against assaults or ships and galleys, they made a third class of piece, lighter in metal and taking less powder, to fire balls of stone. These are the commonly called _canones de pedreros_. All the classes of pieces are different in range, manufacture and design. Even the method of charging them is different." [Illustration: Figure 22--TRAJECTORIES. Maximum range of eighteenth century guns was about 1 mile. _Guns could:_ Batter heavy construction with solid shot at long or short range; destroy fort parapets and, by ricochet fire, dismount cannon; shoot grape, canister, or bombs against massed personnel. _Mortars could:_ Reach targets behind obstructions; use high angle fire to shoot bombs, destroying construction and personnel. _Howitzers could:_ Move more easily in the field than mortars; reach targets behind obstructions by high angle fire; shoot larger projectiles than could field guns of similar weight.] It was most important for the artillerist to understand the different classes of guns. As Collado quaintly phrased it, "he who ignores the present lecture on this _arte_ will, I assert, never do a good thing." Cannon burst in the batteries every day because gunners were ignorant of how the gun was made and what it was meant to do. Nor was such ignorance confined to gunners alone. The will and whim of the prince who ordered the ordnance or "the simple opinion of the unexpert founder himself," were the guiding principles in gun founding. "I am forced," wrote Collado, "to persuade the princes and advise the founders that the making of artillery should always take into account the purpose each piece must serve." This persuasion he undertook in considerable detail.