english: And to do that meant creating the flattest gradients that had ever yet been made, which meant building long viaducts across river valleys -- this is actually the viaduct across the Thames at Maidenhead -- and long tunnels such as the one at Box, in Wiltshire.
non_english: Ve bunu yapmak, daha once hic yapilmamis olan duz zemini yaratmak demektir, nehir vadisinde karsilikli uzun viyadukler kurmak demektir. Bu da Maidenhead'deki Thames'in karsi tarafindaki viyaduk ve Wiltshirei Box'taki gibi uzun tuneller.