GB355242A - An improved instrument for determining the magnetic meridian - Google Patents
An improved instrument for determining the magnetic meridianInfo
- Publication number
- GB355242A GB355242A GB1494930A GB1494930A GB355242A GB 355242 A GB355242 A GB 355242A GB 1494930 A GB1494930 A GB 1494930A GB 1494930 A GB1494930 A GB 1494930A GB 355242 A GB355242 A GB 355242A
- Authority
- GB
- United Kingdom
- Prior art keywords
- tube
- magnetic
- determining
- cradle
- pivot
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
- G01C17/00—Compasses; Devices for ascertaining true or magnetic north for navigation or surveying purposes
- G01C17/02—Magnetic compasses
- G01C17/04—Magnetic compasses with north-seeking magnetic elements, e.g. needles
- G01C17/10—Comparing observed direction with north indication
- G01C17/12—Comparing observed direction with north indication by sighting means, e.g. for surveyors' compasses
Landscapes
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Optical Devices Or Fibers (AREA)
Abstract
355,242. Magnetic tests and measurements. CONNOLLY, T. F., 45, Dryburgh Road, Putney, London. May 15, 1930, No. 14949. [Class 37.] An instrument for determining the magnetic meridian comprises a light tube a, which either is itself a magnet or has magnets b fixed to it, carried in a cradle e which is suspended on a pivot g. The tube a carries a sighting device such as an optical system comprising lenses c and an index or scale d. The tube a is mounted in the cradle e so that it can be revolved about its axis, a milled nut i enabling the jewel f to be raised off the'pivot g whilst this is done. Two readings are taken, the tube a being rotated about its axis through 108‹ before the second reading. The mean of the two readings gives the magnetic North. The sighting system can be used in the reverse direction as a collimator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1494930A GB355242A (en) | 1930-05-15 | 1930-05-15 | An improved instrument for determining the magnetic meridian |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1494930A GB355242A (en) | 1930-05-15 | 1930-05-15 | An improved instrument for determining the magnetic meridian |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB355242A true GB355242A (en) | 1931-08-17 |
Family
ID=10050378
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1494930A Expired GB355242A (en) | 1930-05-15 | 1930-05-15 | An improved instrument for determining the magnetic meridian |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB355242A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2703255A (en) * | 1952-10-13 | 1955-03-01 | Penwell Harold | Magnetic sun visor |
-
1930
- 1930-05-15 GB GB1494930A patent/GB355242A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2703255A (en) * | 1952-10-13 | 1955-03-01 | Penwell Harold | Magnetic sun visor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Clark | Plane and geodetic surveying for engineers: Plane surveying | |
| US1766037A (en) | Piezo-electric crystal apparatus | |
| US2337587A (en) | Navigation guide | |
| GB355242A (en) | An improved instrument for determining the magnetic meridian | |
| US2432958A (en) | Navigation instrument | |
| GB370510A (en) | Improvements in or relating to sunshine gauges | |
| GB409365A (en) | An instrument for the measurement of the radius of existing railway or road curves or the like | |
| GB478557A (en) | Improvements in or relating to polarising devices | |
| GB387776A (en) | Apparatus for reading a divided circle | |
| GB541948A (en) | Improvements in or relating to theodolites | |
| Martin et al. | The measurement of chromatic aberration on the Hilger lens testing interferometer | |
| US2366016A (en) | Optical instrument | |
| GB368410A (en) | Improvements relating to the determination of the direction of the horizontal component of the earth's magnetic field | |
| GB197307A (en) | Improvements in compass-fitted theodolites | |
| GB584532A (en) | Improvements in instruments for calculating variations in the altitude of the sun | |
| GB274185A (en) | Improvements in or relating to sextants | |
| GB368700A (en) | Improvements in and relating to combination surveying instruments | |
| GB350587A (en) | Improvements in magnetic compasses | |
| Baker | Engineers' Surveying Instruments, Their Construction, Adjustment, and Use | |
| GB270245A (en) | Improvements in or relating to stellar observation instruments | |
| GB615183A (en) | Improvements in scale reading devices for instruments for measuring angles | |
| Simms | A Treatise on the Principal Mathematical Instruments Employed in Surveying... | |
| GB293921A (en) | Improved apparatus for the mechanical solution of trigonometrical problems | |
| Ljungdahl | On certain sources of error in determinations of magnetic declination | |
| Nakashima | A Method for Measuring Refractive Indices under the Microscope |