The idea that squeezing crystals has electrical consequences is not new. A phenomenon called piezoelectricity, which is exploited in pressure sensors and quartz watches, involves creating a voltage between the ends of a piece of crystal by applying pressure.
The John Hancock Center was completed in 1970, and its gently sloping black steel form remains one of the most-recognizable structures in Chicagoâs famed skyline. John Hancock Center The John Hancock Center (centre building) on North Michigan Avenue in Chicago. Â© Chicago Architecture Foundation A bold form was chosen for the Hancock Center. The tapered rectangular tubeâwith giant trusses on each of the four sidesâreadily shows how the building is supported.
Rand McNally Buildings. < -- 1 Previous Up Nextâ>. The lot upon which the Central Trust Company Illinoisâ building once stood was cleared by the Great Fire of 1871, and remained vacant until 1880, when the building shown below was erected upon it and was occupied by Rand & McNally.