LONGEVITY OF PERSONS ENGAGED IN DIFFERENT OCCUPATIONS.

The annexed statement, prepared by order of the Legislature of Massachusetts, may be serviceable to life insurance companies, as showing the mean average of life attained by individuals engaged in various employments :-

Some curious statistics, in relation to life and its chances, were given in a paper that was some time since read by Dr. Barton, of New Orleans, before the American Medical Association. Among the results stated, were the following, showing the comparative mortality in eight of the cities of the New World :-1 death in 48.87 persons.

Boston....
Philadelphia.
Charleston

Havana...

Baltimore

New York.....

Mexico

New Orleans...

1

66

48.92

The following relates to nine of the leading cities of the Old World :

London......

90,396 30

The following curious table shows the ratio of deaths in 100,000 persons in

100,000 25 years...

49,995

66

46,758

Figures like the foregoing, says the Philadelphia Inquirer, are well calculated to induce one to pause and meditate. It will be seen that in five years the mortality rapidly diminishes; and at 10 the probability of life is 48 years. At 20, it is 40 years; at 30, 34 years; at 40, 27 years; and at 50, 20 years. It should be remembered, however, that much depends as well upon the mode of living, the temper, the character, and the occupation, as upon the location. This may be readily inferred by the comparative mortality in the cities above named, as well as by an examination of the chances of those who are engaged in the various trades, occupations, and employments into which the members of the human family are divided. A modern French philosopher has endeavored to prove that the life of man might, as a general rule, be extended to a hundred years. This, however, may be regarded as doubtful, although it is quite certain that with care, caution, and prudence, much might be accomplished in the way of longevity.

POSTAL DEPARTMENT.

BRITISH POST-OFFICE-MAILS FOR LIBERIA.

In our notice in April, 1858, (vol. xxxviii., page 495,) of the postal convention between Great Britain and the Republic of Liberia, which went into effect April 1st, 1858, we summarily stated the rates of postage from the United States and Great Britain to Liberia. We now publish the details of the official notice, not because of their own intrinsic importance to the commercial world, but since they exhibit and illustrate the general regulations and comparatively low rates of British ocean postage to distant countries.

The following rates are substituted for those previously levied :

Letters not exceeding oz., 6d.; above oz. and not exceeding 1 oz., 1s. ; above 1 oz. and not exceeding 2 ozs., 2s.; above 2 ozs. and not exceeding 3 ozs., 3s., and so on, adding two rates for each additional ounce or fraction of an ounce. The postage must in all cases be prepaid. Letters addressed to Liberia may be registered, provided the postage, together with a registration fee of 6d., be paid in advance. Newspapers addressed to Liberia, and posted in conformity with the usual regulations, will be chargeable with a postage of 1d. each, which must be paid in advance, and no charge whatever will be made on the delivery of the newspapers in Liberia. Book packets may be forwarded to Liberia at the following reduced rates of postage, which must be prepaid, and no further charge will be levied in Liberia :-For a book packet not exceeding 4 ozs., 3d.; above 4 ozs. and not exceeding pound. 6d.; above pound and not exceeding 1 pound, 1s. ; above 1 pound and not exceeding 14 pound, 1s. 6.; above 1 pound and not exceeding 2 pounds. 2s., and so on, adding 6d. for every additional pound or fraction of a pound.

A book packet may contain any number of separate books or other publications, prints, or maps, and any quantity of paper, parchment, or vellum; and the books or other publications, prints, maps, etc., may be either printed, written, or plain, or any mixture of the three. Further, all legitimate binding, mounting, or covering of a book, publication, etc., or of a portion thereof, will be allowed, whether such binding, etc., be loose or attached; as also rollers in the case of prints or maps, markers (whether of paper or otherwise) in the case of books; and, in short, whatever is necessary for the safe transmission of literary or artistic matter, or usually appertains thereto; but no patterns or books of patterns (un

less consisting merely of paper) will be allowed. The following regulations must be observed:-1. Every packet must be sent either without a cover or in a cover open at the ends or sides. 2. A book packet must not contain any written letter, closed or open, nor any enclosure, sealed or otherwise closed against inspection; nor must there be any letter, or any communication of the nature of a letter, written in any such packet, or in or upon its cover. 3. No book packet must exceed two feet in length, width, or depth.

POST-OFFICES OF SWITZERLAND.

The official returns show the number of travelers and of letters in Switzerland as follows:

Of the 24,322,358 letters, 15,774,509 were inland, and 6,237,740 foreign; 2,310,109 were free. The gross receipts rose from 4,898,327 francs in 1849 to 8,279,989 francs in 1857. The expenses were 6,756,125 francs. The surplus in the last year was, in spite of the opening of 100 miles of railroad in the Cantons, 1,523,864 francs.

POSTAL REVENUE OF THE UNITED STATES.

The revenue of the Post-office Department for the quarter ending December 31, 1857, as exhibited by the adjustment in the office of the Auditor of the Treasury for the Post-office Department, of the quarterly accounts of 27,040 postmasters, is as follows:

Net revenues..

Amount of stamped envelops and postage stamps used during the quarter..

$886,551 58

1,297,850 59

IMPROVED MAIL FACILITIES.

The Postmaster-General, in conjunction with a Convention of Railroad Presidents, has recently made some most important arrangements for facilitating the conveyance of the great Southern mail between this city and New Orleans. The route to be taken south of this city, is by the way of Washington City, Richmond, Lynchburg, Knoxville, Chattanooga, Tennessee, and the Memphis and Charleston Railroad, to the Grand Junction, and thence over the Mississippi

Central, the New Orleans, Jackson, and Great Northern Railroads. The contract has been made, and will go into effect about the first of July, when the time will be reduced from seven to a little over four days. At the expiration of the year the same roads are to be prepared to carry a double daily mail at an increase of only fifty per cent upon the price paid for the single daily mail. A contract has also been entered into by the Postmaster-General for the conveyance of the California mails from New Orleans over the Tehuantepec route twice a month, to be delivered in fourteen days at San Francisco. This latter project is stoutly resisted by a rival claimant of the right to the Tehuantepec route, and the settlement of this question will be looked for with interest by all interested in the improvement of the mail arrangements between the cities on the Atlantic seaboard and the great commercial center of our Pacific coast.

RAILROAD, CANAL, AND STEAMBOAT STATISTICS.

CANALS IN THE UNITED STATES.

The annexed table furnishes, we think, the first complete list of the canals in the United States given to the public. It was compiled by RICHARD S. FISHER, Esq., a gentleman possessing very extensive and accurate information in relation to the public works and the geography and topography of the United States:

With the river improvements, which are mainly found in Kentucky, where, by a series of dams and locks, several rivers have been rendered navigable to an extent of about 600 miles, the aggregate length of the canals of the United States is 5,131 miles.

Were it not for an unrivaled system of railroads, the extent of our canals would be a subject of general admiration. They were so before the construction of our railroads. As it is, they perform a most important function in the internal commerce of the country.

The leading work of the kind is, as is well known, the Erie Canal. It connects the harbor of New York with the great lakes. It is the greatest artificial artery of commerce in the world. It is not only the commercial outlet for the great lakes, but is the trunk of numerous canals connecting the former with the Mississippi, through its various tributaries. There are six independent works of the last-named description, viz. :-The Beaver and Erie Canal, the Ohio Canal, the Miami Canal, the Wabash and Erie Canal, the Illinois and Michigan Canal, and the Fox River Improvement, cutting the country into seven distinct subdivisions, entirely surrounded by water.

Of the New York canals, all, with the exception of the Erie, Oswego, and Champlain Canals, have been more or less superseded by railroads. Such is also the case with the canals of Ohio, Indiana, and Illinois, though these still transact a large amount of business. They are, however, steadily losing their relative importance.

Next to the Erie, the most important canals of the country are located in Pennsylvania, and extending into the coal fields-the Delaware and Raritan, and the Chesapeake and Delaware Canals. The canals engaged in the transportation of coal are the Delaware and Hudson, the Schuylkill, the Lehigh, the Delaware Division of the Pennsylvania Canal, and the Chesapeake and Ohio Canals. The three first named, with the Reading Railroad, are the great coal carriers of the country. They transport to tide-water more than 5,000,000 of tons annually.

The Delaware and Raritan Canal is an important work, as it forms the great

inland route of commerce between New York and Philadelphia. It has a capacity for vessels of 500 tons. The Chesapeake and Delaware Canal is also an important work, of large capacity, connecting Chesapeake and Delaware Bays. A canal capable of passing large vessels and steamboats is also in process of construction between Chesapeake Bay and Albemarle Sound. These several works form an internal coast line of navigable waters, for large class coasting vessels, for nearly the whole Atlantic front of the United States. In case of war such a line would prove of great value in keeping up a communication between the North and South.

It is not probable that canals of any considerable extent will be constructed for the future. Nearly all the available routes are occupied. The only important line, the early completion of which is now urged, is the James River and Kanahwa Canal. When this is completed, the construction of new lines of great extent may be considered as at an end.

In the list we have not embraced the canals of Canada, which are works of great importance, and which are largely used by the people of the United States. These are among the finest works of the kind in the world, and with the Sault Ste. Marie Canal, render the St. Lawrence and great lakes navigable from their sources to the ocean.