Bunsen Burner: Central Gas Jet, Air Holes and Mixing Tube (Roscoe & Schorlemmer, Treatise on Chemistry I, 1905)

The laboratory gas burner. Gas from a hose comes out of a small central jet in a block on a heavy base; as it rushes up the tube above, it draws air in through holes in the block, and the mixture burns at the top with a hot, smokeless, pale blue flame of two cones. Close the holes and it burns with an ordinary yellow luminous flame. Result: a burner giving a hot non-luminous flame for laboratory heating. Source: H. E. Roscoe and C. Schorlemmer, A Treatise on Chemistry, vol. I (1905), §§ 462-463, Figs. 188-189. Unknown: materials and sizes. Picture: the book's Figs. 188-189.