that defendant's truck was weaving back and forth across its side of the highway and that on several occasions it passed across the center line. They testified further that the movements of defendant's truck were such that they did not deem it safe to attempt to pass it. They followed about 300 feet to the rear of the truck. They testified that they saw the accident and each described it as follows: The *224 Prucka truck driven by plaintiff's decedent was traveling west and was at all times on its right-hand side of the highway. They each testified that immediately prior to meeting the Prucka truck, defendant drove his truck to the right and onto the 12-inch curb on his right-hand side of the highway. They said thatas he turned his truck back toward the center of the road, the front end of the trailer crossed over the center line and was hit on the left front corner by the Prucka truck. They said, also, that the rear of the trailer whipped around and that it also was hit by the Prucka truck. These two witnesses were strangers to all the parties to the action prior to the accident; they were in a position to see, and their evidence is unequivocal.
The defendant testified that he was driving a 2-ton tractor with a 32-foot, factorymade, flatbed trailer. The trailer was hitched to the tractor by means of a fifth wheel and a kingpin. When so connected the front of the trailer has no side movement. Mr.