In addition to the very light and therefore easily portable mountain howitzer used for Indian warfare, United States artillery of 1850 included 12-, 24-, and 32-pounder field, 24-pounder and 8-inch siege and garrison, and the 10-inch seacoast howitzer. The Navy had a 12-pounder heavy and a 24-pounder, to which were added the 12- and 24-pounder Dahlgren rifled howitzers of the Civil War period. Such guns were often used in landing operations. The following table gives some typical ranges: _Ranges of U. S. Howitzers in the 1860's_ Caliber Elevation Range in yards 10-inch seacoast 5 deg. 1,650 8-inch siege 12 deg.30' 2,280 24-pounder naval 5 deg. 1,270 12-pounder heavy naval 5 deg. 1,085 20-pounder Dahlgren rifled 5 deg. 1,960 12-pounder Dahlgren rifled 5 deg. 1,770 [Illustration: Figure 36--ENGLISH MORTAR ON ELEVATING BED (1740).] From earliest times the usefulness of the mortar as an arm of the artillery has been clearly recognized. Up until the 1800's the weapon was usually made of bronze, and many mortars had a fixed elevation of 45 deg., which in the sixteenth century was thought to be the proper elevation for maximum range of any cannon. In the 1750's Mueller complained of the stupidity of English artillerists in continuing to use fixed-elevation mortars, and the Spanish made a _mortero de plancha_, or "plate" mortar (fig. 37), as late as 1788. Range for such a fixed-elevation weapon was varied by using more or less powder, as the case required. But the most useful mortar, of course, had trunnions and adjustable elevation by means of quoins. [Illustration: Figure 37--SPANISH 5-INCH BRONZE MORTAR (1788).] The mortar was mounted on a "bed"--a pair of wooden cheeks held together by transoms. Since a bed had no wheels, the piece was transported on a mortar wagon or sling cart. In the battery, the mortar was generally bedded upon a level wooden platform; aboard ship, it was a revolving platform, so that the piece could be quickly aimed right or left. The mortar's weight, plus the high angle of elevation, kept it pretty well in place when it was fired, although English artillerists took the additional precaution of lashing it down.