Transit instrument by John Bird

Transit instrument

John Bird

Fine art poster

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  • Amazing giclée print quality
  • 280gsm thick fine art print paper
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We use a 280gsm fine art paper and premium branded inks to create the perfect reproduction.

Our expertise and use of high-quality materials means that our print colours are independently verified to last between 100 and 200 years.

Read more about our fine art prints.

Manufactured in the UK

All products are printed in the UK, using the latest digital presses and a giclée printmaking process.

We only use premium branded inks, and colours are independently verified to last between 100 and 200 years.

Delivery & returns

We print everything to order so delivery times may vary but all unframed prints are despatched within 2-4 days via courier or recorded mail.

Delivery to the UK is £5 for an unframed print of any size.

We will happily replace your order if everything isn’t 100% perfect.

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Transit instrument

This transit instrument was commissioned by Astronomer Royal James Bradley in 1749 and remained in use until 1816. It was erected a little to the east of Halley's earlier meridian instruments marking out a new north-south line (or meridian) referred to today as 'Bradley's meridian'. It was on Bradley's meridian that the first Nautical Almanac, published in 1767 was based. It was also the meridian used for the first ordnance survey maps based on triangulation carried out in 1787.

A transit instrument is a telescope pivoted on a stand so that it can only move in one plane. Normally this would be aligned north-south so that as the Earth turns, every star visible from the latitude of the telescope can be seen to rise and fall over the course of a year. These types of telescopes can be used to create star charts, since every star can be viewed and so plotted. The time at which each star crosses the north-south line, or meridian gives one co-ordinate, the angle the telescope must point at to see it (its angular height) gives the other. It can also be used to find the time by the stars.
John Bird

  • Image reference: f8696

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