You can, however, mount the lens with the pivot point at or over the center-line of the lens and then lay it with ease - provided you have divided the weight fore and aft of the pivot. This is the principle of the wimberley-styled head.
One of the neatest we have seen recently in the shop is the Induro. Standard 3/8" hole on the bottom and 1/4" thread on the top but an infinity of up/down and fore/aft adjustment to balance the lens. Firm secure lock in final position if that is what you need - easy movement if you are following a target.
Perfect answer for wildlife, birds, and sports.