The Seismograph Adventure
"The Seismograph Adventure" is a scientific detective story by Arthur B. Reeve featuring Professor Craig Kennedy, a criminologist at a New York university, and his journalist companion Walter Jameson. The case begins when Dr. James Hanson, a coroner's physician, visits Kennedy seeking help with the mysterious death of Mary Vandam, the wife of Henry Vandam, an elderly and very wealthy retired banker. Mrs. Vandam was discovered unconscious in her library late at night and never regained consciousness. Her death presents a baffling medical puzzle: she cannot definitively be classified as a suicide, murder victim, or natural death. A pillbox of morphine-containing capsules is found nearby, but the symptoms do not match a clean diagnosis of morphine poisoning, since her pupils were neither symmetrically contracted as morphine poisoning would predict, nor unsymmetrically dilated as kidney failure would suggest. Complicating matters is Henry Vandam's deep involvement with a spiritualist medium named Mrs. May Popper and her manager Howard Farrington. The elderly man believes thoroughly in spirit communications and claims to receive nightly rappings at precisely twelve-thirty from a spirit called "John," who allegedly relays messages from his deceased wife. These rappings originally warned Vandam on the night of his wife's death that something was wrong, and subsequent nightly sessions have been urging him to have the prescription refilled. A new will is being prepared in favor of Mrs. Popper. Kennedy's first move is to attend a midnight session at the Vandam mansion, secretly placing in the spirit cabinet a highly sensitive seismograph of his own construction, modeled on a design by Prince Galitzin of the Imperial Academy of St. Petersburg. Unlike ordinary seismographs, this instrument features two pendulums and two recording drums, allowing it to register not only the magnitude but also the direction of vibrations. When the rappings occur at twelve-thirty, Kennedy's instrument silently records the footsteps and movements of whatever flesh-and-blood entity approached the cabinet wall from the adjacent hallway. Meanwhile, Kennedy instructs Jameson to visit Mrs. Popper for a private séance and to arrange for her and Farrington to attend a circle at Kennedy's laboratory the following night. He also sends Inspector O'Connor to intercept the newly filled prescription before Vandam can take any of the capsules, and to collect ink samples from all relevant parties. Kennedy's chemical analysis of the original prescription and of one altered capsule reveals the murderer's method: a harmless capsule had been replaced with one containing a lethal dose of morphine combined with atropine, or belladonna. The atropine counteracted the telltale pupil contraction associated with morphine poisoning, deliberately deceiving medical examiners. The ink analysis of the handwriting on the prescription matches the ink belonging to Mrs. Popper. For the climactic confrontation, Kennedy transforms his laboratory into an exact replica of Mrs. Popper's séance room, placing the cabinet adjacent to a hallway. He invites all parties, including Vandam, Hanson, O'Connor, Mrs. Popper, and Farrington, and during the séance O'Connor crawls into the cabinet and catches Mrs. Popper producing the rappings with her own toes. After this exposure, Kennedy presents his full chain of evidence: the chemical proof that atropine was mixed with morphine to disguise the poisoning, the ink analysis linking Mrs. Popper to the forged prescription, the tampered capsules intended to kill Vandam as well, and finally the seismograph records. Kennedy has each person in the room walk down the imitation hallway individually and compares each person's seismic trace against the trace recorded in the Vandam mansion. When he implies the trace matches Farrington, both Mrs. Popper and Farrington lunge at the recording papers in a desperate attempt to destroy the evidence, confirming their guilt. Kennedy reveals that the trace in fact matches Mrs. Popper herself, who had used her key to the Vandam mansion to enter nightly, produce the fraudulent spirit rappings, and manipulate the credulous old man into altering his will in her favor, having already poisoned his wife and prepared a second poisoned capsule for him. Inspector O'Connor places Mrs. Popper under arrest for the murder of Mary Vandam and the attempted murder of Henry Vandam.
By Arthur B. Reeve · First published 1916 · Genre: Mystery, Crime Fiction, Detective Fiction