@article{oai:repository.dl.itc.u-tokyo.ac.jp:00000277,
 author = {GRAY, THOMAS},
 journal = {Transactions of the Seismological Society of Japan},
 month = {},
 note = {application/pdf},
 pages = {137--139},
 title = {ON A SEISMOGRAPH FOR REGISTERING VERTICAL MOTION},
 volume = {3},
 year = {1881}
}