Show dust as air a shield tit the british royal commission ii minus mines lins made some interesting ox ex on 00 explosions of mixtures es of coal dust and nin air it lins fins demon grated that such mixtures are eigil bently explosive arid and also vint that the explosions plo can call be mitigated or confined ill urea area by means of stone clu dust clust st which Is not lot explosive A coal dust area was placed between a 11 dustless dust lesa region and one spread with stone dust after which mi all explosion was produced in the lite coal dust hy by ihring a cannon the re stilts appeared to denion demonstrate strate that the ef facts of an explosion may he be transmitted to a considerable distance over a dustless dust du atless lesa zone by the coal dust driven before the air blast but that the stan shonu dust tins has a i restraining effect washington star |