18 (2) The onus of properly enclosing, packing and sealing any insured article lies upon the sender, and the Postmaster shall assume no liability for joss arising from defeers which may not be observed at the time of posting. 61. Conprtions Sprectanrty Appnicasin To InsurepD Lerrers. Letters to which the insurance systin is applicable are those which con- tain bank notes, currency notes, bonds, coupons, securities and other documents of the like kind. Pocuments of value such as deeds, plans, contracts, authographs and rare manucripts inay also be sent by insured post: Provided that where documents have a value by reason of the cost of their preparation, the insured value may not exceed the cost of replacing them in case of lors. 62. ConDITIONS SPECIALLY APPLICABLE ‘To INSURED BoxEs. Articles of gold and silver, precious stoves, jewellery and articles of alike nature may be sent in the letter mails as insured boxes. Insured boxes must be strongly made of metal or wood and wooden boxes must not be less than one-third of an inch thick. 68. Us ayy Renan or Private Lerren Boxes. (1) Private letter boxea shall be of two sizes and shall be rented to the public at the following annual rates: — Small size $3.00 Large size $5.00 to be paid to the Postmaster annually in advance in January of each year. (2) (i) A private letter box will only be rented to one firm, company or person. Gi) All letters addressed to individual members of a firm or company, or to the care of a renter or to any member of his family, or to any person for whom a renter ix agent, may be placed in the private letter box rented to such respective firm, company or person. (3) Renters of private letter boxes will he required to pay for any injury or damage done to such box by them or their sents, (4) When the ase of a private letter box is dixeontinucd the key originally handed ro the renrer shall be returned to the Postmaster in good order. (5) When a private letter box is rented an amount of $2.40 in addition to the rent of the box shall be deposited with the Postmaster by the renter asa guarantee for the safe return of the key when the use of the box is discontinued.