The roads or highways, by land or sea, designated by law as the ave- nues over which the mails shall be transported. Railway Mail Service Cases, 13 Ct. CI. 204. A “post route,” on the other hand, Is the appointed course or prescribed line of transportation of the mail. U. S. v. Koch- ersperger, 26 Fed. Cas. 803; Blackham v. Gresham (C. C.) 16 Fed. 611. POST-TERMINAL SITTINGS .