Yes, these are also under farmland, in a disused Cotswold underground stone quarry. We joked that this was crystallised sheep's piss, but it's arable land above. And like Tim Rose's Portland caves, "There's only 5 to 10 m of 'ground' above this and the soil layer is pretty thin." So, uric acid...

I know that copper stains calcite blue, and iron gives a red colour, but what creates a yellow colour, as in the attached photo?

Take a look at the Gary Storrick collection: http://www.verticalmuseum.com/VerticalDevicesPage/Rappel/FixMultiPages/FixMulti0409.php, and following. A big drawback with these devices was their weight. They're basically a great lump of metal.

I think there's a typo here! After quickly referring to my ancient copy of 'Northern Caves', would you mean Batty Wife Cave?

Nope. Same as my reply to Chris, enterable cave entrances only!

No, they don't! I'm after cave entrances close to, or within, pub/bar premises. I dare say there are bars in cave dwellings, but I'm not going to count these.

It has been suggested (April 2023 UBSS Newsletter) that the Hunters' Lodge Inn Sink is the 'closest cave to any pub (probably in the world!)' I know of one cave which is actually entered through the garage of a bar. Do you know of any other contenders?

Continuing this theme, there was no 'Beer-ometer' on display at the bar. How did we do this year, compared to previous years?

From the trailer I've just seen, it looks like next Tuesday's episode of 'Dan and Helen's Pennine Adventure' will feature them descending Alum Pot. I dare say some of you were involved in making this episode. Will they go back up, or will they come out through Long Churn ...?

Where are these boots, Tom? And 'all the others' you find? I'm putting together a database of places where discarded boots are found. They seem to be in all sorts of mines, all over the country.

Yes, with your main man (Lee Berger) suggesting homo naledi navigated the cave by lighting a series of fires along the way, there would have had to have been a decent airflow, otherwise bad air would have soon been a problem. Where is it you're reading about 'alternative theories'?

Shouldn't that be 'Said the (disappointed) actress to the bishop'?

A fascinating film on Netflix. Well-filmed, no excess lighting. It was interesting to see how non-cavers managed underground: "We only go through this crawl one at a time, in case it collapses."!

I knew that, Chris. I was just pulling your chain!

Sorry, Chris? The Federation Francaise de Speleologie?

Thanks again, Mike, and Rhys. Rhidian Roberts and Roger Smith together is very promising. I hope the Spring 1960 'Signpost' magazine can give more information.

Thanks, Mike. BNS were definitely among the likely suspects. Do you know if Russell is still alive? And if so, do you know how I can contact him? I suppose a pm would be the most discreet way.

It was 'Steiner forgot his wellies' on another trip.

Chelsea SS have recently been investigating several high-level passages off Main Passage in Agen Allwedd. They have been visited before, but there are no records of who was involved. In one of them is scratched the date 1961 and some initials, 'RR' and 'RS'. I have not been able to match these...

I have some questions which I hope the electronically-knowledgeable among you might answer. I have a pack of rechargeable NiMH batteries (nominally 6V, 2.7 Ah) that I charge using a home-made charger. The method I use is to charge them at 0.27 A (the Ah rating divided by 10) for 14 hours. If my...