Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Of the utmost importance in every department of constructional work. The principal forms of strue tural iron and steel have been described and illus trated, as well as the manner in which they may be practically applied as ties, struts, columns, and beams. Roofs and other framed structures have not come under notice, for no incidental reference to so comprehensive a subject could possibly be useful or satisfactory. SO far as building construction is concerned, there can be no doubt whatever that the age of steel is still in its infancy, and if the architect of the future is to be, as he ought to be, the master Of his pro fession in all its branches, he must inevitably make it his business to become thoroughly familiar with all the details of iron and steel construction.