What we buy
We buy a wide range of vintage scientific instruments, from Victorian brass telescopes to mid-century surveying equipment. If it was made with precision and has age, we want to hear about it.
- Brass telescopes — single-draw, multi-draw, and library telescopes by Dollond, Broadhurst Clarkson, Ross, Negretti & Zambra, and others
- Sextants and octants — marine navigation instruments by Heath & Co, Troughton & Simms, Hughes & Son, Kelvin & Hughes
- Microscopes — brass compound microscopes by Ross, Beck, Swift, Watson, and Zeiss; field microscopes and accessories
- Barometers — aneroid barometers, pocket barometers, stick barometers, wheel barometers by Negretti & Zambra, Dollond, Short & Mason
- Compasses — prismatic compasses, marching compasses, pocket compasses, ship’s compasses; military issue and civilian
- Binoculars — military binoculars (WW1 and WW2 marked), Zeiss, Leitz, Ross London, Barr & Stroud
- Surveying equipment — theodolites, levels, plane tables, dumpy levels by Stanley, Troughton & Simms, Cooke
- Drawing instruments — cased sets of compasses, dividers, protractors, and rulers in original fitted cases
What makes a scientific instrument valuable
Five factors drive value in vintage scientific instruments, and understanding them helps you know whether what you have is worth selling:
- Maker: Named makers command premiums. Negretti & Zambra, Stanley, Troughton & Simms, Dollond, Ross, and Heath & Co are among the most collected names in British scientific instruments. Continental makers such as Zeiss and Leitz are equally sought.
- Material: Brass instruments are the most collected. Lacquered brass in original finish is preferred. Chrome and aluminium instruments from the mid-20th century have a smaller but active market.
- Condition: Working instruments are worth more than non-working ones, but even non-functional pieces by named makers have collector value. Original optics, undamaged scales, and legible engravings all add value.
- Completeness: Instruments with original fitted cases, accessories, and documentation are worth significantly more than bare instruments. A sextant with its mahogany case and spare filters, or a microscope with its objectives and slides, will always fetch more.
- Case: Original cases — mahogany boxes for sextants, leather cases for binoculars, fitted boxes for drawing sets — add meaningful value and confirm provenance.
Value indicators by category
Telescopes: A single-draw Victorian brass telescope by a named maker in working order with original lens cap can be worth £80–£300. Multi-draw telescopes and library telescopes by Dollond or Broadhurst Clarkson can exceed £500. Unmarked telescopes have modest value but are still worth assessing.
Sextants: A cased sextant by a named maker such as Heath & Co or Troughton & Simms in working condition with original mahogany case typically ranges from £200–£800. Earlier examples and unusual variants can exceed this.
Barometers: Pocket barometers by Negretti & Zambra or Dollond in original cases are highly collectable, often £100–£400. Aneroid wall barometers by quality makers have a strong market. Stick barometers are assessed on maker, wood, and condition.
Binoculars: Military-marked binoculars (especially WW2 with broad arrow and date) by Ross, Barr & Stroud, or Kershaw are actively collected. Zeiss and Leitz binoculars retain value across eras. Consumer binoculars from the 1980s onwards have limited value.