"This is an improved seismograph," he explained, "one after a very recent model by Prince Galitzin of the Imperial Academy of St. Petersburg. The seismograph, as you know, was devised to register earthquakes at a distance. This one not only measures the size of a distant earthquake, but the actual direction from which the earth-tremors come. That is why there are two pendulums and two drums.英文原著 · 《The Silent Bullet》
"The magnetic arrangement is to cut short the vibrations set up in the pendulums, to prevent them from continuing to vibrate after the first shock. Thus they are ready in an instant to record another tremor. Other seismographs continue to vibrate for a long time as a result of one tremor only. Besides, they give little indication of the direction from which the tremors come.英文原著 · 《The Silent Bullet》
"I think you must all appreciate that your tiptoeing up the hall must cause a far greater disturbance in this delicate seismograph than even a very severe earthquake thousands of miles away, which it was built to record."英文原著 · 《The Silent Bullet》
"No, the record of the ghost on the seismograph was not Mr. Farrington's, as I implied at the moment when you so kindly furnished this additional proof of your guilt by trying to destroy the evidence. The ghost was you, Mrs. Popper, and you are at liberty to examine the markings as minutely as you please, but you must not destroy them. You are an astute criminal, Mrs. Popper, but to-night you are under arrest for the murder of Mary Vandam and the attempted murder of Henry Vandam."英文原著 · 《The Silent Bullet》