Thursday 24 January 2008

10-line Key and Lamp Unit

10-line Key and Lamp Unit in use at Shackerstone. Click on image to enlarge.

This key and lamp unit allows the signalman to speak to any one of ten incoming 2-wire telephone circuits. This type of equipment in varnished wooden cabinets was already old-fashioned when I started to learn about telecommunications in the 1960s. The two volumes of 'Telephony' by Atkinson were the telecommunications 'Bible' and gave an insight into the principles used.

On the left of the box the operator's handset can be seen, hanging from the 'Gravity Switch'. Originally, this would have been a heavy, bakelite 'Hand Micro-Telephone' ('HMT') but it has been replaced by a more modern, and much lighter, '700' series model. The handset cord terminates in a Plug which connects with a Jack mounted on the cabinet.

The horizontal row of coloured knobs in the middle of the front of the cabinet are 3-position Lever Keys, one for each outgoing line. They're often called 'Kellog Keys' after the original manufacturer. Lifting the key upwards sends ringing current to the associated line, so as to ring the bell of the remote telephone. The key is biased so that it returns to the normal position as soon as the operator lets go. This is called 'Non-locking' action. Pushing the key downwards connects the operator's handset to the associated line, so that two-way speech is possible. In this direction, the key will stay down when the operator lets go, leaving the operator with one hand free during the conversation - useful if written notes are required. This is called 'Locking' action. At the end of the call, the operator flicks the lever key back to the central position, disconnecting the telephone he was speaking to.

Below the row of lever keys is a metal 'Lamp Strip'. This mounts ten lampholders accepting plug-in filamentary lamps, usually the British Post Office No. 2 'wedge' lamp. An opal white glass lens fitted in a clip-in brass mounting is fitted in front of each lamp. When any of the remote telephones initiates a call, the appropriate lamp glows white and a buzzer (common to all lines) sounds until the operator pushes the associated key down to the 'SPEAK' position. This action silences the buzzer and allows a conversation to take place.

British Weather

Mid-November 2007: Brewood is frosty and cold.
It's amazing that I've not specifically written about the British weather before. It's usually the first thing we talk about when we meet someone - "Isn't it cold?", "Isn't it hot?". The English have an remarkable capacity for finding the weather unsatisfactory, whatever it's like. In general, England has very temperate conditions, never very cold, never very hot. Until I travelled a little, I'd no personal experience of the extremes that some countries suffer on a recurrent basis, although I am old enough to remember (just!) the severe winter of 1947 in England. Snow fell in unprecedented quantities and life became a major challenge as transport faltered. Perhaps it was a hangover from the "Britain can take it" philosophy of the Second World War but I rather fancy that people generally coped better then than in recent times. It seems that only a few snowflakes need to descend today before train services are completely disrupted and our road system gridlocks. Then again, even before the snow comes, train services are usually disrupted and roads gridlocked.

No sooner had I commented in an earlier post on the lateness of Autumn in 2007 than the weather turned very cold and we had heavy frosts. Then it turned very wet. The weather seems to have ricocheted between frost, sun and rain ever since. In this area, we've had sleet but no proper snow, so far. I didn't enjoy the cold, but the heavy frosts can be visually attractive.

Mid-January 2008: The arch of Brewood Hall Bridge is almost filled with flood water.

Since Christmas, we've had an awful lot of rain and the ground is now very sodden. Many parts of the country are, once again, under threat of serious flooding with the attendant misery to families involved. On 20th January, at least one of the roads out of my village was flooded but passable. The brook which runs opposite my home was at a higher level than I've seen for a number of years.

In contrast, today, it's quite mild, although with a rather chill wind. It's pleasantly sunny with a blue sky and fluffy white clouds. At least the variety of English weather means you don't get bored!

Pictures of Brewood Hall Garden through the Seasons.