What was done in the latter during the first year after the discovery may be read in an article by Dr. Apjohn in the _Dublin Penny Journal_ for December 27, 1834, an article reproduced from the _Dublin Geological Journal_, vol. i. Dr. Apjohn carried out a most elaborate and painstaking survey to points considerably beyond the second great cavity, now known as the "House of Lords," but failed to reach "O'Leary's Cave," the key of the farther ramifications, or to explore the tunnels connected with "The River." His plan, worked out to scale, and showing the differences of level with great minuteness, remained the only map of the cave until M. Martel's survey in 1895. Meanwhile various adventurers had got to more distant points, particularly to the long chain of caverns running east to Brogden's, at the end of which M. Martel's chart stops. The French explorer does not seem to have broken any fresh ground; but his plan, which appeared in _The Irish Naturalist_ for April 1896, with an account of his visit, was a brilliant achievement, especially when the short time at his disposal is considered, six hours for the whole of the cavern. Parts of this chart were only hastily sketched in, either from a rapid survey or from information supplied by the guide, as M. Martel explained to me in a conversation some time ago, and errors of detail were, under these conditions, unavoidable. For instance, "O'Leary's Cave" is much larger than appears on the plan, and the "Chimney" is not situated at the far end of a passage, but actually opens in the floor of "O'Leary's Cave." The caves running east, again--O'Callaghan's and Brogden's--are not such a simple series of straight passages as they seem on the chart; our guide had considerable difficulty in threading his way among the various bifurcations. As will transpire later, there is a mystery connected with the name of "Cust's Cave," the real Cust's being in a totally different part of the series, and a different chamber altogether in shape. Unfortunately we did not go prepared to carry out any survey, believing that all this had been done; so that we can at the most point out some places where the existing plans are at fault. We were also unfortunate in not being prepared to take a large number of photographs, the accounts we had read not leading us to anticipate the actual grandeur and extent of the scenery. M. Martel compares the Mitchelstown Cave with such famous continental caverns as those of Adelsberg, Padirac, Dargilan, and Han-sur-Lesse, and it comes off but poorly in such a comparison. I have seen his lantern slides of these caves, and after exploring all the most beautiful caves discovered as yet in England, I venture to say there is not one English cave that would not come off badly if set beside any of these. Compared, however, with other British caverns, that of Mitchelstown can hold its own easily; though individual chambers may be surpassed, there is nothing