In the general scheme of mail bags used in the postal service the term “pouch” is used to apply to all mail bags designed for locking by means of mail locks, and the term “sack” is used to apply to all mail bags used in the postal service which are designed for closing but not locking. Under the term “pouch” may be mentioned those bags used for inclosing through registered mail, saddle bags, designed for transportation of mail on horseback; inner registered bags, used for holding registered matter and inclosed in another receptacle; and the ordinary pouches for first class mail matter such as letters, etc.; also the mail catcher pouch, the use of which is restricted to the exchange of mails with moving trains. Under the term “sacks,” which are designed for closing, as a rule, but not locking, comes the ordinary sack for newspapers and parcel post matter, and bearing a cord fastener which bears a label case and also serves for closure purposes. The standard bag is made of No. 8 canvas, of best quality, and withstands usage for several years. The sacks used for foreign mails, ordinary and registered, are not provided with a closure device but are tied with a string and secured with a lead seal, but it is expected in the near future these classes of bags will be equipped with a locking contrivance. During the last ten years the weight of pouches used for ordinary service has been rapidly diminishing. The average weight of pouches in 1907, largest size, was about 9 pounds 5 ounces each, while those now being introduced into the service weigh 2½ pounds each. This reduction in weight being due largely to the elimination of leather parts. Many old-style pouches are still in use, viz., made of a heavy canvas body, leather bottom and a light weight top; costing about $2.16 each; the “1908” pouch made of a heavy canvas bottom with leather band and a lighter weight canvas top and body, costing about $1.44 each. These pouches are now being rapidly replaced with the all-canvas pouch costing less than 70 cents each. Catcher pouch used in the exchange of mails on moving trains costs 80 cents each. Wherever possible, the Department has eliminated expensive leather and other parts in the production of its equipment. There are approximately 600,000 pouches and 4,000,000 sacks available to the service at present. The all-canvas pouch which the Department now furnishes costs between 69 and 70 cents, while the largest size domestic standard sack cost a little less than 73 cents, smaller sizes in proportion. Pouches and sacks are purchased by contract but kept in repair by the Government. New pouches of new types are also manufactured by the Government, nearly 80,000 being made in the Mail Bag Repair Shop during the past year.