You say: Solar energy? What do you mean?

The agenda and the participants of the 40 years ago Mont Louis Internationa l Colloquium on Solar Energy are looked at, and it is obvious that the bulk of the meeting is devoted to solar furnaces although not exclusively. This coincides to the profile of the CNRS Solar Energy Laboratory founded in 19 48 according to the will expressed in a motion signed by 11 academicians al l specialists in the field of high temperature and inorganic chemistry and metallurgy. At the issue of a campaign of research in using a solar furnace in Meudon there were enough evidences established by Tombe's team to justi fy the construction of a large solar furnace for new high temperature capab ilities and practical applications on hand. The main contributions by Tromb e and Foex are identified to be. the non contaminant self-crucible melting using focused solar radiation, the hot spot specific features and the coupl ing of solar Furnace and other sources like plasma gun. The analysis of dif ferent cases of high temperatures approaches since Moissan with his electri c furnace all through today's research shows a surprising continuity in eff iciently creating new objects in the sense of M. Berthelot.