The Early Years of Human Flight
In the 1850s, inventors realized that early balloon technology had its limits. A French engineer, Henri Giffard, came up with a concept of “a craft that was lighter than air.” In 1852, he designed the first aircraft by connecting a steam engine to a large propeller. However, aircraft wouldn’t become popular until the gasoline-powered engine was invented in the 1890s. Gas engines enabled Ferdinand von Zeppelin to design his amazing flying machine, the Zeppelin.
到了 1850 年代，發明家們認知到早期的氣球科技有其侷限。一名法國工程師亨利．吉法發想出了「一艘比空氣還輕盈的飛船」的概念。1852 年時，他藉由將蒸汽引擎連結至一個大型螺旋槳而設計出了第一架飛機。但一直到了 1890 年代使用汽油驅動的引擎發明問世時，飛機才變得普及。燃氣引擎讓斐迪南．馮．齊柏林得以設計出他驚人的飛行機器 ── 齊柏林飛船。
concept [ `kansEpt ] n. 概念
Time is an abstract concept.
connect A to B 將 A 連結到 B
enable sb to V 使某人能夠做……