In his last book, published posthumously, Gower reflected on the gigantic advances made in the use of iron and steam. He noted this especially on the railroads where passengers and heavy freight travelled at the extraordinary velocity of thirty miles per hour. He thought that, because of the need for large coal bunkers, 'steam paddlers' were unlikely to replace sail on long trade routes such as the trans-Atlantic crossing. He hoped that vessels of the "Transit" type would ply across the Ocean until "more portable means shall be invented for putting steamers in motion". Just five years later SS Sirius and Brunel's SS Great Western crossed the Atlantic under steam power alone. Gower was correct in pointing to the need for large bunkers, the former vessel had to burn furniture and fittings to complete her record-breaking voyage, while the latter arrived a day later with 200 tons still in her bunkers.