You will need to contact the owner's representative to arrange access.
In the case of this object this can be done by:
Calling 0207 747 2885
Writing to The National Gallery, Trafalgar Square, London, Wc2n 5dn
Reporting A Data Error:
Reporting An Access Error to the HMRC:
A mid-Georgian signal barometer and perpetual regulation of time
Maker:  Maker Unknown
A mid-Georgian signal barometer and perpetual regulation of time, inscribed 'F.Watkins fecit', in the form of a diagonal barometer, thermometer and date recorder, also showing phases of the moon, sunrise and sunset, the fixed feasts, etc. calibrated from 1731 to 1830, in glazed mahogany case with engraved explanation and illustrations representing the Four Seasons (losses) Francis Watkinsfl. 1747-1784 (?)
Currently kept at: Longford Castle
THIS ARTWORK IS LOCATED IN:Wiltshire
At Longford Castle - Guided tours are available on 28 days a year during the Spring Summer and early Autumn. Tours to be booked through the contact point. Numbers for each tour are limited so early booking is advisable. Tour dates for 2014: March 31st ; April 1st 2nd 3rd 4th and 5th ; May 12th 13th 14th 15th 16th and 17th ; July 16th 17th 18th 19th 20th 21st 22nd and 23rd ; September 4th 5th 6th 8th 9th 10th 11th and 12th . For these tours, booking is through the National Gallery via the website at the following link: http://www.nationalgallery.org.uk/whats-on/calendar/longford-castle Access is also available for special interest groups (of not more than 20 persons) by pre-booked tours. Special interest groups should book with The Tour Manager, Longford Castle, Salisbury, SP5 4ED; email@example.com / 07880 006 131. Dates for 2014 are: April 2nd and 5th ; May 13th and 16th ; July 18th 20th and 22nd ; September 5th 9th and 11th . Booking for special interest groups is on a first come first served basis, so early booking is recommended. Access is available at other times for research or study whether or not as part of an academic arrangement, by making arrangements through the Tour Manager (contact details above).