The Canadian National Steam book series provides rail enthusiasts, model railroaders, historians -- plus those interested in all things mechanical and on wheels -- with a wealth of information about Canadian railway technology, and specifically about the motive power developments of Canada's largest railway system. Canadian National Railways' 'X' class was assigned road numbers 1-99 primarily for the narrow gauge locomotives of the former Prince Edward Island Railway, as well as various standard-gauge dinkey and tank engines with various driver diameters. The class, totalling forty-four locomotives, came from three predecessor roads, mainly Grand Trunk Railway of Canada and Canadian Government Railways stock. One was acquired from Canadian Northern Railway via the Mount Royal Tunnel & Terminal Company Limited. Class 'A' was assigned road numbers 100-199 for 4-4-0 American (Standard) or Eight-Wheel Types with drivers 63 inches or less. The class, totalling 74 locomotives, came from three predecessor roads, the Grand Trunk Railway of Canada, Canadian Northern Railway and Canadian Government Railways. Class 'B' was assigned road numbers 200-399 for American (Standard) or Eight-Wheel Types with drivers more than 63 inches. This class, all 4-4-0s, totalled 185 locomotives taken into stock from four predecessor roads: the Grand Trunk Railway of Canada and its USA lines, Grand Trunk Pacific Railway, Canadian Government Railways, and Canadian Northern Railway. On the 1949 day Newfoundland joined the Canadian Confederation, CNR inherited forty-six locomotives in four wheel arrangements from the island railway. Six of these (five 4-6-0s and one 2-8-0) dated back to the Reid-Newfoundland Company Limited lease of the Newfoundland Railway. The remaining forty (ten 4-6-2s and thirty Mikados) had all been built for the Newfoundland Railway. The last Mikado Types arrived the same month as Confederation.