The Chartwell mining transit book, model 2637 features slightly larger squares on the graph printing (5 mm square) as opposed to the 2647 variation. The 2637 is again, suitable for use in the mining sector in mine surveying or for other geological based surveying applications. Made form 50% rag bond paper with 80 waterproof pages, a bright yellow hard back cover to protect against damage, weather, water and is easily visible if put down. the printing on the pages of the mining transit survey book feature 5 red vertical lines with faint blue horizontal writing lines on one side and a 5 mm square graph page with a single red vertical line on the other.
