The Scent-Cone is the secret to understanding what dynamic makes hunting dogs classier and more accomplished in hunting and handling game.
Most of the great bird dog trainers/handlers I knew grew up with a pack of hounds. I’ll name four: Clyde Morton, Paul Walker, Er Shelley, Bob Armstrong. They learned most about scent from running foxhounds. One of these, Er Shelley, even took a pack of hounds to track game when he traveled to Africa.
Imagine that the concentration of scent effluvium is weaker at the outside of the cone (which is in actuality three dimensional like a funnel). Of course, the cone or funnel is extremely unstable, subject to breezes, dust-infusions, temperatures, and barometric pressure. Thus, while essentially narrow where it is laid down, and broadening out, it floats, billows and shrinks and wafts around without any pattern but its very own.