Unfortunately I think that takes the original 8mm ( known as straight or standard 8) film which came as a roll of 16mm film which you exposed down half of one side and then turned over at the end of the 25 feet to expose the other half side, giving you 50 feet. When developed, the film would be slit down the middle and joined each end. (As you turn the film over in subduded light, about 6 feet of the film will come out overexposed as its been exposed to the light). Kodak's later Super 8 comes as a cartridge making it much easier to load.
I recently acquired a straight 8mm camera and the film is quite expensive (In Britain at least) and processing is also a fortune. I actually worked out its cheaper to buy the film from the USA or Germany and get it processed in Germany than it is just to buy the film in the UK, even when you include the postage.
BTW, Speilberg started out with 16mm and Super 8 film, not the earlier standard 8.