Used in a Marconi spark gap transmitter
Condenser Plates, Marconi Towers
Electric charge for the transmitter spark was stored in a very large condenser (modern name: capacitor). It consisted of 288 sixty foot by twenty foot metal sheets that were suspended from the rafters of the transmitter building and extended down almost to ground level. These sheets filled most of the building, which consequently was called the "condenser building".
Assuming a six inch gap between plates, someone else calculated the total capacitance to be 1.86 uF.