"I had a course in East Hall just before," I explained. "I couldn't seem to make it in time." "Well, it's time you learned to be on time," he growled. Then his eyes twinkled. "Time!" he ejaculated. "The most fascinating word in the language. Here we've used it five times (there goes the sixth time--and the seventh!) in the first minute of conversation; each of us understands the other, yet science is just beginning to learn its meaning. Science? I mean that _I_ am beginning to learn." I sat down. "You and science are synonymous," I grinned. "Aren't you one of the world's outstanding physicists?" "One of them!" he snorted. "One of them, eh! And who are the others?" "Oh, Corveille and Hastings and Shrimski--" "Bah! Would you mention them in the same breath with the name of van Manderpootz? A pack of jackals, eating the crumbs of ideas that drop from my feast of thoughts! Had you gone back into the last century, now--had you mentioned Einstein and de Sitter--there, perhaps, are names worthy to rank with (or just below) van Manderpootz!" I grinned again in amusement. "Einstein was considered pretty good, wasn't he?" I remarked. "After all, he was the first to tie time and space to the laboratory. Before him they were just philosophical concepts." "He didn't!" rasped the professor. "Perhaps, in a dim, primitive fashion, he showed the way, but I--_I_, van Manderpootz--am the first to seize time, drag it into my laboratory, and perform an experiment on it." "Indeed? And what sort of experiment?" "What experiment, other than simple measurement, is it possible to perform?" he snapped. "Why--I don't know. To travel in it?" "Exactly." "Like these time-machines that are so popular in the current magazines? To go into the future or the past?" "Bah! Many bahs! The future or the past--pfui! It needs no van Manderpootz to see the fallacy in that. Einstein showed us that much." "How? It's conceivable, isn't it?" "Conceivable? And you, Dixon Wells, studied under van Manderpootz!" He grew red with emotion, then grimly calm. "Listen to me. You know how time varies with the speed of a system--Einstein's relativity." "Yes."