canadacelebrates150years.ca is always looking for great content to help promote Canada and this 1919 book about using airplanes to create aerial photgraphy in Canada is in depth and well written. If the text is not to your interest, some of the photographs will be. To view it for FREE head to Archive.org https://archive.org/stream/airplanephotogra00ivesuoft#page/n433/mode/2up