There are, of course, several intermediate stages in the progress of the packet from the place of posting to the place of delivery. Under the most favourable circumstances, as in the case of a letter from one small town to another small town for which there is a direct mail, the packet is handled two or three times by various officers; and in many cases, as with the letters from a suburb of one large town to a suburb of another large town, or to a place in a rural district or vice versâ, as many as ten or twelve times. Although the character of the service to be performed, viz. transmission to the place of its address, is identical in every case, the character of the packet naturally has considerable influence on the nature and cost of handling at the various stages, and the methods adopted in dealing with the packet. But the operations are in essence the same, and the chief difference is in the amount of time occupied and the nature of the office fittings employed. This variation of cost and method does not correspond with variation in the rate of postage paid on the packets. Except in the case of parcels, all distinction on the basis of rates of postage disappears once the sorting office is reached. In regard to the chief indoor operations there is, except at the smallest offices, complete separation between packets sent by parcel post and all other packets; but parcels are in some cases taken out with other packets for delivery at the same time and by the same officer. Except in rural districts they are, however, generally taken out separately for the first morning delivery, and frequently for the last evening delivery. Speaking broadly, there is as regards delivery, as for other operations, essential separation between parcels and all other classes of packets. In regard to packets other than parcels, the chief, and in many cases the only, separation in actual handling is as between those packets which can be passed through the stamping machine and those which cannot; and between those packets which can conveniently be dealt with at the ordinary letter-sorting frames, and tied in bundles for enclosure in the mail-bags, and those which on account of their irregular size and shape are sorted at pigeon-hole frames, and cannot be tied in bundles, but are forwarded loose in the mail-bags. The dividing line is almost identical in both cases, and is determined by the size and shape of the packet. In the largest offices more divisions are made, in some cases as many as five.[613] The more usual number is three, "short letters," "long letters," and other packets.[614] The division of the packets is made in all cases, not with reference to the various rates of postage under which the packets may have been posted, but with the view simply of securing that packets of the same shape and size shall, as far as possible, be brought together, and their subsequent handling thereby facilitated.