01
Engraved Maker Inscription
Clear period hallmark reads 'LAWRENCE & MAYO LONDON Nº 513' stamped directly into the horizontal limb edge.
Curio Gallery
01 / 05
01 / 05Lawrence & Mayo Transit Theodolite No. 513 — photograph 4
Highlights
Why this object
still matters.
A classic British vernier transit theodolite by Lawrence & Mayo of London, engineered for precision surveying and civil engineering. Finished in black enamel with exposed lacquered brass scales and verniers, the instrument features a full vertical circle, sensitive spirit levels, and a three-screw leveling tribrach base.
02
Full Vertical Circle
Equipped with a finely divided brass vertical circle and dual vernier reading magnifiers for zenith angle measurement.
03
Stout A-Frame Standards
Rigid black-lacquered dual-standard frame supporting the central transit telescope axis without flexure.
04
Precision Spirit Levels
Features multiple adjustable tubular spirit levels mounted on the horizontal plate and upper standards for exact leveling.
05
Three-Screw Tribrach Base
Classic geodetic tribrach design featuring large knurled brass leveling screws and a threaded tripod mount socket.
06
Surveyor's Telescope
Equipped with brass objective end cap, knurled focusing controls, and an eyepiece with diopter adjustment.
Specifications
The useful facts,
clearly recorded.
Measurements, construction, identity, and seller-supplied details are kept together for direct comparison.
Reviewed · Curio catalogue
Maker
Lawrence & Mayo, London
Origin
United Kingdom
Year
1913
Department
scientific-instruments
Packed shipment
4 kg · 40 × 30 × 25 cm
Maker Mark
LAWRENCE & MAYO LONDON Nº 513
Instrument Type
Vernier Transit Theodolite
Materials
Enameled brass/bronze, silvered scales, optical glass
Leveling Base
Three-screw leveling tribrach with knurled thumbscrews
Vials
Dual tubular spirit levels mounted on plate and vertical standards
Optics
Terrestrial surveying telescope with rack-and-pinion focusing and objective cover
Details
Close inspection,
recorded in photographs.
Detail № 01 · Lawrence & Mayo Transit Theodolite No. 513 — photograph 1
Detail № 02 · Lawrence & Mayo Transit Theodolite No. 513 — photograph 2
Heritage
A traceable life,
carefully recorded.
Provenance documentation was not supplied for this specific Lawrence & Mayo Transit Theodolite No. 513; this listing is based on the supplied photographs only.
Imperial Engineering
Mapping the Modern World
Surveying instruments like this transit theodolite formed the backbone of British railway construction, municipal surveying, and geographical triangulation, providing the rigid mechanics necessary for uncompromised accuracy across demanding colonial terrains.
London Craftsmanship
The Signature of Lawrence & Mayo
Each instrument produced by Lawrence & Mayo underwent exhaustive hand-finishing, with its serial number and London provenance permanently engraved into the brass dial, attesting to rigorous optical and mechanical calibration before leaving the workshop.
Timeline
An object in time,
one continuous story.
1868
Founding of Lawrence & Mayo
Lawrence & Mayo is established in London, quickly expanding into optical, navigational, and surveying instruments across the British Empire.
1877
Expansion into India
The firm establishes offices and workshops in Bombay and Calcutta to supply precision instruments to railways and government surveys.
1913
Production of Transit No. 513
Transit theodolite serial number 513 is manufactured in London for high-accuracy field triangulation and civil engineering works.
1930s
Transition to Optical Micrometers
Traditional open-vernier transit theodolites gradually give way to enclosed glass-circle tachymeters and modern optical designs.
Condition
Honest wear,
documented clearly.
The theodolite displays authentic historical wear with edge chipping, rubbing, and paint loss across the black-enameled A-frames and base casting. The brass scales, knurled adjustment screws, and vernier readouts show natural patina and minor surface oxidation. Glass spirit levels and telescope lenses appear intact with expected dust and superficial handling marks.
✓
InspectedEnamel Finish
Visible chipping, paint flaking, and edge wear down to the underlying brass on the standards and barrel.
✓
InspectedBrass Components
Even aged patina and surface oxidation on adjustment wheels, scale rings, and thumbscrews.
✓
InspectedScales & Markings
The maker engraving 'LAWRENCE & MAYO LONDON Nº 513' remains crisp and clearly legible on the lower plate rim.
✓
InspectedBubble Levels
Tubular glass spirit levels remain mounted in brass housings with intact fluid reservoirs.
Logistics
Inspected, insured,
door to door.
Step 01
Delivery
Inspected, photographed, and packed with its condition report.
Step 02
Shipping
Custom-fit protective packing with tracked, insured courier service.
Step 03
Returns
Return requests are accepted within fourteen days of confirmed delivery.
Step 04
Dispatch
Prepared for courier handoff within three to five business days.
Acquisition
Make it part of
your collection.
Contact the seller for more information or to discuss this object.
✓ Insured Shipping✓ 14-Day Returns✓ Condition Report✓ Reviewed Listing
Lawrence & Mayo Transit Theodolite No. 513