| RefNo | ACS/1/1/27 |
| AltRefNo | 5977 |
| Level | Item |
| Title | Letter from [William George] Armstrong, Cragside, Rothbury, to [Alan Archibald Campbell] Swinton, 66 Victoria [Street], London, S.W |
| Creator | Armstrong; William George (1810 - 1900); Baron Armstrong of Cragside; armaments manufacturer and industrialist |
| Date | 18 June 1891 |
| Description | Shares further thoughts pertaining to his and Swinton's experimentation, adding that the rapid destruction of the platinum points is a recognised objection to the use of vibrating contact breakers when large currents are applied to Ruhmkorff coils of considerable size, therefore larger currents than necessary should never be used and the magnets should be sufficiently strong to work with reduced currents. Fails to see what harm there can be in having the magnets abundantly strongfor all the purposes seeing that any surplus strength in the case of large currents can be balanced by increasing the tension of the spring. Recalls that when he criticised the heavy heads of the vibrations, Swinton explained that Mr [Alfred] Apps considered that a sharp recoil and a smart blow on the contact points waws desirable and this would justify the weight of the head and the strength of the spring, but a strong spring requires a strong magnet. States he has one but not the other and therefore cannot realise the advantage of forcible recoil even with the largest current that is practicable to use, for the magnets are not strong enough to pull back the springs when any decided tension is put upon them. Suggests that the solution to the difficulty is to subsitute new magnets of greater strength wound with wire of sufficient thickness not to heat. Objects to all unnecessary complications and makeshifts. Maintains that if larger magnets are applied they should be fixed in independent frames and the present standards should be cut down to mere seats which he believes could be easily managed. |
| Extent | 2p |
| Format | Manuscript |
| PhysicalDescription | Ink on paper |
| AccessStatus | Open |
Fellows associated with this archive
| Code | PersonName | Dates |
| NA3460 | Armstrong; William George (1810 - 1900); Baron Armstrong of Cragside; armaments manufacturer and industrialist | 1810 - 1900 |
| NA8285 | Swinton; Alan Archibald Campbell (1863 - 1930); electrical engineer | 1863 - 1930 |