Most of the objects in this collection are ghosts of hardware, silhouettes of machines that have gone. The parcel is different. Multipart never had any hardware to lose, because it was never a physical thing at all. It is a pure idea, the registry's way of shipping several things as one, and so there is no shell to sit behind glass, only a method the exhibit asks you to picture.

The picture is a parcel, and it is a good one. When a message needs to carry more than a single item, multipart bundles the pieces together and marks where each one ends. It does this with a boundary string, a run of random characters chosen to be unlike anything in the contents, laid between the parts the way packing tape separates the things inside a box. Open the parcel and the boundary tells you where one item stops and the next begins. Nothing is glued to anything else; each part keeps its own identity while travelling inside a single shipment.

This is not an antique curiosity but a mechanism in constant use. Every web form upload still ships as multipart, in the particular form called multipart/form-data. When you attach a file to a form and send it, the file and the form's other fields are packed together with exactly this boundary scheme and dispatched as one bundle. It is, in the exhibit's phrase, the cardboard box of the internet: unglamorous, universal, and quietly holding the contents of countless everyday transactions. The parcel earns its place in the collection precisely because it cannot be held. It shows that some of the most durable inventions are not devices at all but agreements, ways of arranging things that outlast any particular machine. The floppy disk vanished and left an icon behind. Multipart never needed a body, and so it simply keeps working, invisible inside nearly every upload we make.