生成一个有趣的科普视频---**Category:** HISTORY **Title:** HOW TO DIG FOR TREASURE **Description:** There's a lot more to a detectorist's hobby than picking up a metal detector and sweeping a field. Here's how to responsibly prepare for a fun day out, detecting techniques and, perhaps most importantly, the law **Author:** WORDS: BEN BIGGS **Image Description:** The image is a photograph showing a pile of antique gold coins. The text is superimposed on this background. There are no charts, diagrams, or tables in the image. **Extracted Text:** **DID YOU KNOW?** The 1,000-year-old Chew Valley Hoard consisted of 2,584 silver coins valued at £4.3 million ($5.6 million) **Main Article Body:** Britain has a deep and chequered history that can be traced across dozens of major cultures right back to prehistoric times. Over thousands of years it has been populated by neolithic hunter-gatherers, the gregarious Beaker people, fractious Celtic tribes and powerful civilisations like the Romans, wielding their influence from faraway lands across the sea. They have invariably warred and squabbled with each other in a tug of war over territory, and sometimes settled into periods of peace and prosperity. It's quite literally a rich history, if we are to go by the fantastic treasures that are pulled out of Britain's muddy fields on a surprisingly frequent basis. Among the stone tools, remnants of ancient dwellings and singular coins or personal items that have been lost, forgotten or abandoned for centuries, are finds whose enormous monetary value is equalled only by their contribution to British history. In July 2009, a metal detectorist sweeping a field in Staffordshire, England, stumbled upon a find that can only be equated to winning the lottery. After Terry Herbert's bargain metal detector, which he had picked up in a car boot sale, lit up like a Christmas tree, he spent the **WHERE TO START** We'll get into the basic detecting techniques and equipment later, but before you get out there and start sweeping any old patch of land, give your metal detector a practice run by burying a few metal objects in your garden or a patch of land you have access to. Then familiarise yourself with the laws surrounding amateur metal detecting in your country. If there's a local metal-detecting club in your area, join it! Not only will you benefit from the experience and advice of seasoned detectorists, you'll have access to group events with permission prearranged with the landowner. Joining a club can be a more fulfilling way of pursuing a metal-detecting hobby **Annotation:** © Alamy **Chart/Diagram Description:** The image contains three main visual components: 1. **Close-up of coins:** A heap of gold-colored coins is shown, some stacked or overlapping. Details of figures, text, and patterns are visible on the coins. This image is in the upper left section of the page. 2. **Group of people:** A group of people is seated outdoors around picnic tables, under trees. They appear to be engaged in a meeting or discussion. Some are sitting on benches, others on folding chairs. A wooden building is visible in the background. This image occupies the lower middle/right section. 3. **Banner/Display Board:** A grey fabric banner or display board is shown hanging from a tree or pole in the lower right section. It features a large diamond shape with a logo inside (which includes text "AWAS INC. FOUNDED 1976" and symbols) at the top. Below the logo, there are rows and columns of rectangular pockets, many of which appear to contain cards with names or other information. The pockets have a blue border. This display is positioned next to the seated group of people. **Title:** HISTORY **Image 1 Description:** Type: Photograph Content: A scuba diver underwater using a metal detector. Caption: Divers can detect shipwrecks using specialised waterproof metal detectors **Image 2 Description:** Type: Photograph Content: A pile of ancient coins on a surface. Caption: A fraction of the 52,503 Roman coins discovered buried in a giant pot near Frome, England **Did you know?** The first metal detectors were developed in the 1800s. **Main Article Text:** next five days carefully digging up hundreds of antiques – buttons, rings, wires, sword pommels and many other gold and silver objects. The fact these ancient artefacts had been cast in precious metals meant he legally had to report it, so he got in touch with the local finds liaison officer Duncan Slarke. Duncan was gobsmacked by the quantity of Anglo-Saxon items Terry had found, and excitedly emailed his colleagues for their opinion on the hoard, saying he thought it was “nationally important”. But those 250 artefacts were just the tip of the iceberg. A month-long excavation ensued, revealing another 1,600 objects, followed by nearly another 3,000 by the time archaeologists finished with the site a few years later. They were mostly of military origin in various states of fragmentation, and are thought to have been trophies collected by an Anglo-Saxon military man. A total of 5.1 kilograms of gold, 1.4 kilograms of silver and around 3,500 semi-precious gems were excavated. The largest Anglo-Saxon hoard ever discovered, it was valued at nearly £3.3 million ($4.3 million) – split between Terry and the landowner. This find was a detectorist's dream that Terry said, to the Birmingham Mail, was “more fun than winning the lottery... money was a plus, but seeing the treasure coming out of the ground was a wonderful experience." The odds of finding something like the Staffordshire Hoard is the equivalent of hitting the jackpot from a single lottery ticket, though that shouldn't dissuade a beginner looking to pursue a fulfilling metal-detecting hobby. Most detectorists spend hours meticulously pacing a few square acres of land in all weathers just to get out in nature, spend time with like-minded members of a club or for the occasional thrill of turning up something small but significant. They might tell you, in one way or another, that their hobby is really about connecting with the history of the land and that even the most common of finds – be it a worn Roman coin or a cavalier's musket ball – has a story. The razor-thin chance of discovering a golden treasure that redefines history can still make them giddy with excitement when their metal detector starts to beep, but that's a fantasy rather than an expectation. **DOS AND DON'TS** [Checked box] Do check the weather forecast before an outing and dress accordingly [Checked box] Familiarise yourself with the laws surrounding metal detecting in your country [Checked box] Seek permission from the landowner before detecting on private land [Checked box] Follow the countryside code by closing gates and respecting plants and animals [Checked box] Immediately report finds such as 'treasure', suspected human remains, bombs or ammunition [Crossed box] Don't detect on protected sites, including scheduled monuments and sites of special scientific interest [Crossed box] Don't leave holes in the ground, always backfill once you've finished digging [Crossed box] Don't leave any litter behind. Take it with you and dispose of it responsibly **WHERE TO LOOK** In the UK, you can legally metal detect in many public places, such as public beaches, parks and playing fields. These can be good places to start if you don't have access to a garden to practice detecting in, as you don't have to seek prior permission and you can still turn up coins and other small finds that you won't necessarily have to declare. But be sure to double-check that you can metal detect on any piece of land first. Some places the public has access to, such as public rights of way, are strictly off limits to detectorists without the landowner's permission. **Image 3 Description:** Type: Photograph Content: A person walking on a pebble beach using a metal detector. Caption: You can usually detect on public beaches without permission in the UK and a few other countries **Textual Information:** **DID YOU KNOW?** Metal detectors are also used to detect buried landmines, bombs and weapons **WHAT YOU WILL NEED** **1 Metal detector** You don't need to spend a lot of money on a metal detector – Terry Herbert's jackpot-finding device cost him less than a cup of coffee. You won't have to raid your savings account to buy a good beginner's single-frequency detector, and though it won't be as effective as a multifrequency detector, it will be easier to use and less expensive. **2 Shovel** A lightweight shovel is essential: standard garden spades are often too heavy and cumbersome to cart around all day. There are plenty of options available for detectorists, including long-handled trowels with foot assists and telescopic shovels that can easily be stowed away in a pack when not being used. **3 Finds pack** You'll need a backpack or satchel to carry your detectorist kit in, and any finds you want to keep, with space for a waterproof coat or warm pullover depending on the weather in the area you're searching in. Over several outings you'll likely find yourself adding more items to your inventory, which might include an insulated flask or bottle for drinks, a sandwich box and a torch. "Their hobby is about connecting with the history of the land" **Other useful items** There are a few other items that experienced detectorists often take with them to make identification and collection easier in the field: a spray bottle of water to rinse loose dirt off excavated items, an old toothbrush to scrub away more stubborn dirt and a coin pod to carry any loose coins – these can often be discovered in small batches that might once have been held in a purse. **Copyright:** © Alamy / Shutterstock **Chart/Diagram Description:** The image is a photographic arrangement of items used for metal detecting, presented as a guide titled "WHAT YOU WILL NEED". The items are laid out on a textured surface. - **Main Items:** Three main categories are numbered and described. - Item 1: A metal detector, disassembled or laid flat, showing the search coil, shaft, control unit (labeled '1'), cables, and headphones. Other accessories like spare batteries and a small digging tool/pinpointer are shown near it. - Item 2: A black-handled spade/shovel (labeled '2'). - Item 3: A camouflage backpack or bag (labeled '3'). A pair of blue and grey gloves and a red object are partially visible inside or nearby. The text "90 cm" is visible near the bag. - **Other Items (grouped):** - A camouflage-cased tablet device displaying a map. - A small orange box. - Zip ties. - A wrapped white object (possibly a cloth or bandage). - A coiled cable with connectors. - A smaller, round black object (possibly another search coil or coil cover). - **Other Useful Items (shown in separate smaller photos):** - A clear plastic spray bottle. - An old toothbrush with pink and blue bristles. - Two old coins placed in a clear plastic container with dividers. The arrangement is informative, showing essential and supplementary tools for metal detecting. HISTORY HOW A METAL DETECTOR WORKS Get to know about this vital piece of equipment before you start Diagram of a metal detector showing numbered parts. 1 SEARCH COIL This consists of a transmitter coil, which generates a magnetic field that goes into the ground, and a receiver coil, which detects metal when the magnetic field passes over it. 2 TO THE CONTROL BOX When the receiver picks up a signal, it sends it to the computer in the control box, which determines whether it's a metal object or something else, like soil mineralisation. 3 TREASURE FOUND If a metal object is detected, the detector makes a beeping sound. The detectorist can hear this through a pair of headphones plugged into an audio jack. 4 LCD DISPLAY Modern metal detectors can distinguish between metals such as gold, silver, iron and copper based on their electrical conductivity, as well as whether the object is likely to be a coin, jewellery or something else. Annotation text: It's not just human-made artefacts that can be found with a metal detector - metal nuggets and meteorites can be detected too. DETECTING TECHNIQUES There are two basic metal-detecting methods you should employ to maximise your chances of finding something: Diagrams showing different metal detector sweeping patterns. Left diagram shows a wide swing with the coil lifted off the ground (crossed out). Right diagram shows a narrow swing with the coil close to the ground (checked). Another diagram shows a grid pattern with arrows indicating sweeping direction. Swinging You may have seen detectorists waving their metal detectors over the ground, but there's more to this than meets the eye. It's vital that you keep the coil of your metal detector close to the ground at all times during each swing or it won't be able to detect properly. Keep the arc of your swing small so that you're not lifting it more than a couple of inches off the surface. It's also important to overlap your swings to ensure you've efficiently detected every inch of the ground in your path. Gridding This is simply the path you take to sweep as much of the ground as possible. On a site that isn't yielding much, this might simply be a case of walking up and down in rows. But on more productive sites you should walk up and down, left to right and diagonally in both directions. Even though it might seem pointless to sweep the same patch of ground again, some targets won't be detected when moving in one direction but will produce a strong signal when swept in another direction. THE LAW Is treasure hunting permitted in your country? Legend for the world map: PERMITTED (Blue color swatch) PROHIBITED (Purple color swatch) PERMITTED BY PERMIT (Orange color swatch) World Map showing different countries colored according to the legend. DID YOU KNOW? In 2024, two UK detectorists who failed to declare a £12 million ($15.5 million) Viking hoard were jailed for over eight years **5 FACTS** INCREDIBLE AMATEUR DETECTORIST FINDS 1. **HENRY VIII'S MISSING CROWN** The solid-gold centrepiece made for the English king's crown was thought to be lost forever after Charles I fled the battle of Naseby in 1645, until a detectorist dug it out of tree roots in a Northamptonshire field in 2021. It was valued at £2 million ($2.6 million). 2. **HAND OF FAITH** This record-breaking gold nugget shaped like a human hand was found under 30 centimetres of soil in Victoria, Australia, in 1980. It's the world's biggest gold nugget found with a metal detector and weighs in at over 27 kilograms. It was sold for the equivalent of $3.5 million (£2.7 million) today. 3. **THE MARYBOROUGH METEORITE** A 4.6-billion-year-old space rock was discovered by a gold prospector in Victoria, Australia, in 2015. It weighs 17 kilograms and is thought to have fallen to Earth between 100 and 1,000 years ago. 4. **COENWULF COIN** A unique, 1,200-year-old gold coin featuring a portrait of the English king Coenwulf was found near the river Ivel in England in 2001. It was bought in 2006 for £357,832 by the British Museum. 5. **SANTA MARGARITA CHALICE** While searching in shallow water off the Florida coast in 2008, a detectorist dug up what he thought was a beer can at first, but turned out to be a 17th-century gold chalice that sank with a Spanish ship called the Margarita in 1622. It was valued at over $1 million at the time. **WHAT IS TREASURE?** There's a legal definition of 'treasure' in England, Wales and Northern Ireland that was established under the 1996 Treasure Act. Essentially, any gold or silver item that is at least 300 years old, any group of ten or more base (non-precious) metal coins that are at least 300 years old, a group of two or more prehistoric base metal items or anything found with a treasure object, should be considered treasure. A similar but broader law exists in Scotland. **What if you find it?** Treasure needs to be reported to the county finds liaison officer or a local museum within 14 days of discovery. There are finer points to the legal definition, but a good rule of thumb is that if you dig something up that you're unsure of, report it. If your find is deemed to be treasure and a museum expresses an interest in it, a committee will have the treasure valued and you will be entitled to a share of its value, possibly half if you're splitting it with the landowner. **What if it's not treasure?** If you're detecting on someone else's land, you need to inform the landowner of anything you find and want to take away, even if it's not treasure. In England, Wales and Northern Ireland, you don't have to report non-treasure antiquities, although you are encouraged to record them on the Portable Antiquities Scheme (PAS) database. This will help the UK's national picture and build a fuller history of the land on a local and possibly national level. Did you know? Nearly 2 million objects are recorded on the PAS database **THE SENIOR TREASURE REGISTRAR AT THE BRITISH MUSEUM** *Image Description:* Photo of Ian Richardson, identified as the Senior Treasure Registrar, in front of bookshelves, holding a metal object (part of a Bronze Age hoard). Annotation: Ian Richardson holding part of a Bronze Age hoard at the British Museum Annotation: Trustees of the British Museum Annotation: Ian Richardson and his team are responsible for acquiring and assessing thousands of treasure items found across Britain. **What stage in the process are you involved in?** I would say most of it - almost all of it is what our team keeps track of. Basically, when someone finds something that they suspect meets the definition of treasure, we need to put it through the legal process. We monitor and keep track of it and do little bits of processing along the way, all the way up until either no museum wants to acquire the find, so it's disclaimed and returned to the finder or landowner, or a museum does want it and it's valued, and they pay that amount of money to us. We pay it out as a reward to the finder and landowner, then it's in that museum's collection. **Have you been involved in a find that has changed historians' view that period of history?** The biggest one that I can think of is probably the Staffordshire hoard, which is a collection of several thousand artefacts, some quite substantial gold and garnet items, mostly bits of weaponry, pieces of sword and helmet. It wasn't found in the traditional areas where lots of high-status Anglo-Saxon artefacts had been discovered previously, in East Anglia and Kent. Finding it in the Midlands meant that it was demonstrating that Anglo-Saxon material culture was quite advanced and prolific throughout England. **Do you have any advice for young treasure hunters?** Go to our website, the Portable Antiquities Scheme, read the advice for finders and the code of practice for responsible detecting. You always have to get the permission of the person who owns the land, and every bit of land in Britain is owned by someone. And if you have a question about what you found, do get in touch with your finds liaison officer. Try to have a relationship with them - there's one in every county in England and covering most places in Wales - so that you can share your finds and hopefully contribute to the archaeological record and our understanding of the past. Beneath Our Feet, by Michael Lewis and Ian Richardson, is available from book stores now. *Image Description:* Photo of the book cover "BENEATH OUR FEET" by Michael Lewis and Ian Richardson, showing a landscape and a small pile of gold objects. Annotation: © AdobeStock / Shutterstock