steam and gas: Mount Etna, Italy (Sicily) Stromboli, Italy (Aeolian Islands) Eyjafjallajökull, Iceland Hekla, Iceland Tungurahua, Ecuador Pacaya, Guatemala Mount Redoubt, United States (Alaska) Mount Aso, Japan (Kyushu) Whakaari (White Island), New Zealand Gunung Slamet, Indonesia (Central Java) Momotombo, Nicaragua (León) See also Bubble ring Vortex ring toy References External links How to puff a smoke ring? Blowing a smoke ring (wikiHow) Smoke rings generated by eruptions of Etna volcano Smoke rings from Stromboli volcano Instructions on building a smoke ring cannon Smoke rings at US Army disposals in Iraq (see images on bottom) Thomson, Sir William (Lord Kelvin), On Vortex Atoms, Proceedings of the Royal Society of Edinburgh, Vol. VI, 1867, pp. 94–105. Silliman, Robert H., William Thomson: Smoke Rings and Nineteenth-Century Atomism, Isis, Vol. 54, No. 4. (Dec., 1963), pp. 461–474. JSTOR link Movie of a modern recreation of Tait's smoke ring experiment How to Blow Smoke Rings - Howiw How To Blow Smoke Rings Vortices Smoke Smoking