Time capsule -- anyone ever done one?

[Sim D.]

Lo all,

Doing a bit of minor outside work and it presents the perfect opportunity to bury a time capsule. Something I've always wanted to do since seeing Blue Peter's abortive efforts as a kid in the 70s.

I've a pretty good idea what I want to put in it [see below], but I'm much less sure about how to preserve the integrity of whatever box I put it in, and how long the contents will last even if the box stays leakproof.

It will be going into ground that is generally damp, but never flooded (yet), and I would be most disappointed if it was discovered within

100 years, and ideally I would like it to last a 1000, if not more, which I realise is probably unrealistic.

Initial thoughts were of some strong galvanised steel waterproof box, with maybe 100 bin liners individually wrapped and tied around it. Then I realised that is going for quantity over quality and if I want it to really last then the box itself is going to have to be the main barrier.

A few thoughts I'd had about some of the contents would be to seal them all in plastic, and place them all in the oven for an hour or so on just over 100° C. to kill any microbial activity. I'd also put silica gel in the box to absorb moisture, and iron filings to absorb the oxygen in a bid to further inhibit any growth.

Any suggestions at all greatly appreciated, how to build it or what to buy, how deep to bury (I do want it discovered eventually), what to put in, and how to preserve both the integrity of the box, and its contents. All the contents will be duplicated in a 'house box' so that we never have the temptation to dig up the real one to check what's inside:)

------------------ {*} contents would include the predictable items such as a selection of that day's newspapers, written letters from each of the family, brief history of the house and family, photographs videos CDs of music and commentary from us all. A video of a trip round the town and some of the local shops. Maps, both national and local. Most of this would also be duplicated onto a computer hard disk drive which I understand preserve their data pretty well, and hopefully they will still somehow be able to read. Currency, a few of the latest hi-tec gadgets [cheap ones obviously] so they can have a laugh. The kids will also have their own little 'secret box' which goes inside with things that only they know about, which has excited them greatly :)

[The3rd Earl Of Derby]

You need a hobby, have you tried DIY?

-- Sir Benjamin Middlethwaite

[Mungo "two sheds" Toadfoot]

We've got one bricked up behind the fireplace in a metal biccy tin. It can't come out unless the brickwork's removed so it should stay where it is for a good few years!

I wouldn't bury one in the ground, personally, because it's quite possible it wouldn't ever be found.

Si

[Alan]

In message , Sim D. wrote

Didn't you imply that you have learnt from the Blue Peter experience? Will anyone be able to play a CD, video or access a hard disk in 100 years time? Isn't there already a problem with the physical longevity of data on such media?

[Rusty]

The council buried one near here last year. They got a stainless steel cylinder about 6" dia x 18" with a screw lid and probably an O ring seal. Cost a hew hundred £.

Nobody believes the contents will survive very long.

rusty

[Ian Stirling]

I'd go with nice old-fashioned stuff. Lead roofing sheet box, welded seams, dipped in pitch, and several layers. Put in a polyproplylene bucket, filled with wax.

[Set Square]

How about using a length of plastic soil pipe with suitable end caps with their own (synthetic)rubber seals etc.?

[Frank Erskine]

I think that for _long_ term burial of artefacts, plastics are best avoided.

[The3rd Earl Of Derby]

Ceramics are a good protecter when burying something. However its finding something large enough and strong for items you have stated.

I worked on a farm in my youth and the tractor was forever upheaving ceramic and glass pottery items dating back to 16th century, clay pipes came up in their hundreds this must have been a kiln area.

-- Sir Benjamin Middlethwaite

[--s-p-o-n-i-x--]

I'd suggest a box fabricated from sheet lead and seam soldered would be your best bet.

Lead lined stone coffins have been discovered dating back thousands of years.

sponix

[Matt]

The only suggestion so far for an outer casing that IMHO stands any chance of lasting!

[Matt]

Burying *any* electronic media is a complete waste of time, photos need very stable conditions to survive intact for more than a few decades and unless the right choice of paper and ink is made that will quickly degrade as well.

Look at items that have in the past survived 1000 years - not very many, then look at the ones that have survived 4000 years - quite a lot when they were stored correctly - replicate what the Ancients, particularly the Egyptians did rather than relying on anything post industrial revolution.

[Andy Dingley]

This will crack under its own weight. If you want to make a long seam in lead, then it needs to be either mechanically joined (a rolled edge) or a welded edge (lead burning).

Depending on the local water. In some conditions the water goes right through them. Lead isn't actually that stable long-term, you need a moderately hard water to build up a surface carbonate layer on it.

[dennis]

Put it all on a cheap laptop. Seal that up (without the battery) and they may be able to access the data in a hundred years or so. Assuming they still have electricity that is.

Anything on computer storage is likely to be unreadable in 100 years time as standards have changed a few times.

[dennis]

Pencil will last longer than ink.

[--s-p-o-n-i-x--]

What about filling the box with a gas to remove the oxygen and prevent oxidisation of the contents?

If it were pressurised it'd also discourage the ingress of water, for a period of time at least.

sponix

[--s-p-o-n-i-x--]

I was assuming that this'd be something maybe 6" cubed. It'd only crack under it's own weight if huge.

Obviously a lead box would need to be placed inside something else (Concrete?) to provide mechanical strength and prevent it being crushed.

So how do lead covered roofs work? The rain water bounces straight off. Rain water is also "soft" so there would be no build up of minerals either.

sponix

[John Cartmell]

Desiccating surroundings.

[Mike Gayler]

It occurs to me with all this talk of lead lined boxes et al, that the finder needs to know that it is a time capsule, and have a method of opening it!

[Anna Kettle]

Conservation Resources sell stainless steel time capsules with silica gel sachets and shreddies (their word not mine) which can be sealed and purged with inert gas. I spex thats the bees knees of time capsules. Should be at 245 pounds for the smallest size

Anna