https://youtu.be/ziDoZ1N0UGM
https://youtu.be/cUPihXHRggY
https://m.youtube.com/watch?v=Gr7D4Bk_t9o
https://m.youtube.com/watch?v=KkTopAcOqJI
https://youtu.be/A81nvDdP5KY
1872- Cyrus Baldwin patents the Hydraulic electric elevator
https://youtu.be/Ln7qw6i-FAI
https://youtu.be/3s7EauUYH9w
https://youtu.be/okIB65YlwaM
https://youtu.be/9mm9PWMEbmM