(Day & Month are approximate.)
Timeline for the tower, extracted from the comments below:
- 1907: 3-storey tower with flat roof built. Timeball operated on roof.
- 1928: April - October, 4th storey with round window, and dome-shaped roof added to raise the height of the timeball so it could be seen from more locations.
- 1933: Timeball removed as the Observatory switched to using radio to transmit time signals.
Booth mentions being able to see the tower - and its 'inverted T' typhoon signal - from his position next to the Peninsula Hotel. The Sheraton Hotel obscures the view today.