The collection includes early televisions, calculators and computers
A collection of early technology that includes pre-war TVs is expected to fetch up to £1m at auction next week.
Bonhams said the collection of 758 items includes many regarded as firsts of their kind.
It belongs to Michael Bennett-Levy, from Edinburgh, who has spent 30 years collecting examples of early technology from across several centuries.
Among the pieces is what is billed by the auction house as an "unequalled" group of 26 pre-war TVs.
Bonhams said it was the most comprehensive collection of its type still held in private hands, with only 500 such televisions thought to have survived.
Also being auctioned are the first LED pocket calculators from 1971, which are estimated to reach between £200 and £300.
The sale will also feature a Bennet electrostatic friction generator from 1770, valued at £8,000-£12,000, and a Wimshurst X-ray machine, set to raise £7,000-£10,000.
Mr Bennett-Levy said: "The first examples in any field of antiques are always important regardless of any other considerations."
Parts from LEO II, created in May 1958, the first commercial computer, are expected to reach £2,000.
Other significant firsts are a rare Cuthbert reflecting microscope from around 1830 - it is estimated at £15,000-£25,000.
There are also the producer's working papers for the opening of the BBC television service on 2 November 1936.