Appearance of the chambers. The miners, when they branch off from the main shaft or avenue, leave pillars of coal about eighteen feet square, to support the roof or mass above. These huge pillars were crushed by the great weight upon them, in the accident recorded.

chambers

Appearance of the chambers. The miners, when they branch off from the main shaft or avenue, leave pillars…

"New Zealand Chambers." — The Encyclopedia Britannica, 1910

Chambers

"New Zealand Chambers." — The Encyclopedia Britannica, 1910

Diagram to show the mode in which successively formed chambers may completely embrace their predecessors, as in Frondicularia.

Successively Formed Chambers

Diagram to show the mode in which successively formed chambers may completely embrace their predecessors,…

"Vertical Section of the Great pyramid, looking West showingA. Entrance passage.       B. A later opening.D. First ascending passage. E. Horizontal Passage.F. Queen's chamber.G G. Grand gallery.H. Antechamber.I. Coffer.K. King's chamber.M N. Ventilating chambers.O. Subterranean chamber.P. Well, so-called.R R R. Probable extent to which the native rock is employed to assist the masonry of the building." - West, 1904

Vertical section of the Great Pyramid

"Vertical Section of the Great pyramid, looking West showing A. Entrance passage. B. A later opening. D.…