Back in the mid 80s, my school sports hall was lit with 250w
Around the same time, I'm sure the 70w lanterns on Bournemouth sea front near my Grandparent's did the same run-up sequence. (did early 70w lamps have snap starters as opposed to glow bottles?) I certainly haven't seen this in recent years so I'm wondering if this is down to improved lamp designs or maybe the supply voltage was low? I'm guessing the lamps were not getting warm enough inside initially to keep the bimetal switch open, causing it to close and restrike, then fully run-up having built up enough heat inside. Thoughts?