The city's central geographical position, its extensive railway connexions, and its proximity to important coal-fields have combined to make it one of the principal industrial centres of the Middle West. The value of its "factory" products was 17.6% of the state's total in 1900 and 20.9% of the total in 1905. The increase in the value of the "factory" product between 1900 and 1905 was from $59,322,234 to $82,227,950, or 38.6%. Indianapolis is the principal live stock centre of the Ohio Valley, and has extensive stock-yards covering more than 100 acres. Slaughtering and meat-packing is the most important industry, the value of the product amounting to $24,458,810 in 1905; this industry dates from about 1835. Among other important manufactures are foundry and machine shop products ($6,944,392 in 1905); flour and grist-mill products ($4,428,664); cars and shop construction and repairs by steam railways ($2,502,789); saws; waggons and carriages ($2,049,207); printing and publishing (book and job, $1,572,688; and newspapers and periodicals, $2,715,666); starch; cotton and woollen goods; furniture ($2,528,238); canned goods ($1,693,818); lumber and timber ($1,556,466); structural iron work ($1,541,732); beer ($1,300,764); and planing-mill products, sash, doors and blinds ($1,111,264). Indianapolis is governed under a form of government adopted originally in a special charter of 1891 and in 1905 incorporated in the new state municipal code, which was based upon it, It provides for a mayor elected every four years, a single legislative chamber, a common council, and various administrative departments--of public safety, public health, &c. The guiding principle of the charter, which is generally accepted as a model of its kind, is that of the complete separation of powers and the absolute placing of responsibility.