英汉大词典第二版修订建议一(Jerkwater)

第1019页，jerkwater 作形容词的第三义项："（火车等）慢的[因原先火车在小地方停车时乘务员不得不用桶到小溪里提水，故名]

我觉得中括号中的解释不甚明了，为什么乘务员就不得不去提水呢？同时，感觉"到小溪里"并不恰当，莫非以前火车站都是追着"小溪"建设？甚至，必须是"小溪"，其他水源都不可以？

今天看Webster的Word of the Day，有下面的详细解释

We owe the colorful Americanism "jerkwater" to the invention of the steam engine ― an advancement that significantly accelerated travel by rail but also had its drawbacks. [B]One drawback was that the boilers of the early locomotives needed to be refilled with water frequently, and water tanks were few and far between. As a result, the small trains that ran on rural branch lines often had to stop to take on water from local supplies. [/B] Such trains were commonly called "jerkwaters" from the motion of jerking the water up in buckets from the supply to the engine. The derogatory use of "jerkwater" for things unimportant or trivial reflects the fact that these jerkwater trains typically ran on lines connecting small middle-of-nowhere towns.

可以看到，这里说的是由于机械设计上尚无法克服的缺陷，早期蒸汽机车不得不开一段后就要停车加水（作机车的"源动力"）。至于水源，则是water tanks，为local supply。至于是谁（是否为乘务员）去哪里（是否是小溪）则无关紧要。[em04]

建议将括号里的部分修改为：
（火车等）慢的[早先蒸汽机车由于设计尚不完善而须不时停车加水方可继续开动，故名]