The criticism has been made that the river steamboat is one of the few modern mechanical contrivances which have shown no particular development, but remain to-day as they were long ago. The criticism is a mistaken one. If comparison be made between the first river steamboats and the best of to-day it will be found that progress in this development is quite up to that in other lines, and it is doubtful if any other machine is more perfectly adapted to its peculiar work. In very recent years there has naturally been but little development, for the steamboat business on Western rivers has largely passed away. [Sidenote: THE FIRST “YELLOWSTONE.”] The earlier boats were usually of the sidewheel pattern, with only one engine, and an immense flywheel to keep it from stopping on the dead point. Unlike the modern boat, most of the accommodations for freight and passengers were abaft of the wheels. The stages for getting on and off were located there. The forward part was mainly taken up with machinery. The men’s cabins were in the hold. The shape of the boat was ill adapted to its work. It had a model keel, which gave it fully six feet draft with half of the load which has since been carried on three feet.[12] [Sidenote: THE MODERN STEAMBOAT.] Far different from this early boat was that used in the later years of business on the Missouri. The first-class modern river steamboat was about 220 feet long and 35 feet wide, and would carry 500 tons. It was built with a flat bottom, so that it would draw, say, thirty inches light and fifty loaded. It was propelled by a stern-wheel, a most excellent arrangement, which had become practicable through the invention of the balanced rudder: that is, a rudder with a part of the blade on each side of the rudder post. There were two engines of long stroke, one on each side of the boat, communicating directly with the wheel shaft and thus avoiding all loss from the friction of gearing. A proper distribution of the weight required that the boilers be placed well forward. This left a large space between them and the engine room, which was well aft. [Sidenote: FIGURATIVE DESIGN.]