Abstract

Summary This article compares the discoveries of the planets Neptune and Pluto and the unsuccessful search of intra-Mercurial planets. Its conclusion is, that the search of intra-Mercurial planets was started on the basis of reasonable assumptions and competently pursued, that the success in the search of Neptune and Pluto and the failure in the search of intra-Mercurial planets was not due to greater competence of the successful planet searchers, but to good luck of the successful researchers and bad luck of the unsuccessful researchers