For his third lecture at one of the Lindau Meetings, Samuel Ting had chosen a title which he in principle would keep as a running title for a total of three lectures, 1985, 1988 and 1991: “Search for the Fundamental Building Blocks of Nature”. This title, as Ting explains in his introduction, is the driving force of his continued work in high energy elementary particle physics. The main reward of the costly experiments he performs is a better understanding of these building blocks. Before the quark model appeared, there were hundreds of particles in what looked like the periodic table of elements. Then the quark model brought this number down with a factor of about ten and brought with it something very similar to the understanding of the periodic table of elements through Rutherfords discovery of the atomic nucleus and Bohr’s model of the atom. In a pedagogic way, Ting follows our view of the proton from the small object of the 1920’s, through the large object of the 1950’s, the large object with structure of the 1960’s to the large object built of point-like quarks of the 1970’s. As he points out, in 1985 there were already on-going experiments to determine if the proton can decay. After listing some other open questions, e.g., how many different kinds of heavy electrons and neutrinos exist, Ting then moves on to his main theme this year, the construction of the new 27 km accelerator ring LEP at CERN and its detectors. In this ring, electrons would circulate one way and positrons the other. In certain places the two beams were brought to collide and Ting himself is involved in a collaboration building one of the huge underground detectors at such a collision point. The collaboration consists of an international team of several hundred physicists and technicians from all over the world. Ting spends considerable time on the design of such a detector and even goes into some technical detail.