The course of instruction consists of ten drills such as has been described, after which the men are called up twice a year, just to refresh their memories. One side of the gallery is glazed, so that the instructor can watch his men at work without of necessity being inside himself, and there are emergency doors as well, which can be opened to let a man out should the ordeal be too much for him. The necessary "fumes" are generated in a stove and driven into the gallery by a fan. The stations are beautifully fitted up, with baths for the men to wash after their somewhat dirty experience in the gallery, and everything is done for their convenience and welfare. The advantage of this systematic training of a great number of men is that there are men at each colliery who can be called upon when needed. The team of strangers, as has been remarked, partially failed at Courrières, largely because they were strangers, but when every colliery has a team ready, composed of its own men, then clearly there is the greatest chance of success. The central station of the district is the training-ground where the men go from all the collieries to get the experience and instruction, and where a reserve store of appliances is kept. In many cases, of course, the collieries have their own appliances, so that work can be begun at once, without having to wait for that from the rescue station, but the latter forms a reserve in case of need, and, being kept under the care of an expert, it is naturally always in the best possible working order. To give an idea of the cost of these stations, it may be stated that the one at Porth, in the Rhondda Valley, cost, including equipment, £7000, while the one at Mansfield cost £3000. This first cost and the expense of maintenance is borne by the collieries of the district in proportion to the quantity of coal which they raise. And now we can turn to the apparatus itself, without which the organisation already described would be of little value.