"Then if not, and if the examination is to begin in five minutes, are we not likely to be late?" I mildly observed.
"Oh, no," replied the doctor, "there are three or four minutes left yet."
"Doctor," said I, "I have been introduced within the last few days to many new and speedy modes of locomotion, but I can't see how you are going to get me to Arlington from here in time for the examination that begins three minutes hence, unless you reduce me to an electrified solution, send me by wire, and have me precipitated back to my shape at the other end of the line; and even in that case I should suppose we had no time to waste."
"We shouldn't have, certainly, if we were intending to go to Arlington even by that process. It did not occur to me that you would care to go, or we might just as well have started earlier. It is too bad!"
"I did not care about visiting Arlington." I replied, "but I assumed that it would be rather necessary to do so if I were to attend an examination at that place. I see my mistake. I ought to have learned by this time not to take for granted that any of what we used to consider the laws of Nature are still in force."
"The laws of Nature are all right," laughed the doctor. "But is it possible that Edith has not shown you the electroscope?"
"What is that?" I asked.
"It does for vision what the telephone does for hearing," replied the doctor, and, leading the way to the music room, he showed me the apparatus.
"It is ten o'clock," he said, "and we have no time for explanations now. Take this chair and adjust the instrument as you see me do. Now!"
Instantly, without warning, or the faintest preparation for what was coming, I found myself looking into the interior of a large room. Some twenty boys and girls, thirteen to fourteen years of age, occupied a double row of chairs arranged in the form of a semicircle about a desk at which a young man was seated with his back to us. The rows of students were facing us, apparently not twenty feet away. The rustling of their garments and every change of expression in their mobile faces were as distinct to my eyes and ears as if we had been directly behind the teacher, as indeed we seemed to be. At the moment the scene had flashed upon me I was in the act of making some remark to the doctor. As I checked myself, he laughed. "You need not be afraid of interrupting them," he said. "They don't see or hear us, though we both see and hear them so well. They are a dozen miles away."