(_f_) The street, &c. should be given on all addresses. Well known persons and firms get their letters, &c. regularly, although this rule may not be adhered to; but the omission frequently leads to delays in the _general_ distribution, and sometimes to serious mistakes. In large towns where many names of firms approximate in appearance somewhat to each other, the addresses of letters cannot be too fully given. With London letters, this rule should be strictly adhered to. (_g_) The number of the house, and the correct one, should be carefully added.[184] When information of this sort is kept back, hesitation and delay frequently occur in delivery; though, perhaps, few letters eventually fail to reach their destination on this account. 5. Every letter should be examined with care before it is dropped in a letter-box, in order to see that it has been securely sealed. Thousands of letters are posted yearly without any precaution of the kind having been taken with them, the Post-Office authorities having to secure them as a consequence.[185] Not only so, but twelve thousand letters are yearly posted without any address at all. 6. Good adhesive envelopes, not too highly glazed, of the ordinary size, are sufficient security for letters,[186] if the adhesive matter has been but _slightly_ wetted. If, for additional security, it be thought advisable also to seal a letter with wax, it should be placed outside the envelope. Very frequently, the wax is found to have been placed on the adhesive matter inside the envelope, thus rendering both ineffective. 7. Letters intended for warm climates should not be sealed with wax at all, inasmuch as there is great danger of the wax melting and injuring the letter, as well as the other contents of the mail-bag. 8. Care should be used in securing newspapers and large packets.[187] Newspapers, when not sent at first from the newspaper offices, should be addressed on the paper itself and tied with string, as great risk is run in the matter of covers becoming detached from the newspapers themselves. Book packets, in addition to being enclosed in covers, sealed with wax, gum, or other adhesive matter (but open at the ends or sides), may be tied round the ends with string, as additional security. When the latter precaution is taken, there is less chance of letters getting within the folds of the packet, which may happen when it is not thoroughly secured. 9. Valuable packets or books, if they cannot be well secured, should scarcely be sent through the post. All such packets are liable to be roughly handled, and in the mail-bags exposed to pressure and friction. When safely deposited in the mail-bags, valuable packets are still in danger, inasmuch as the bags in many cases are constantly being transferred from one kind of conveyance to another, and frequently despatched from railway trains by apparatus machinery whilst the train is in motion.