From the New York Times:
Turning to immigration, Mr. Trump said he had not been joking when he said recently that a wall on the Mexican border would pay for itself if it had solar panels. He also said the wall would have to be transparent, using an offbeat example to explain why.On May 20, 1990, in Los Angeles, Randy Barnes set the world record for the shotput with a throw of 75 feet 10 inches, measured vertically. The shot is an iron ball weighing 16 pounds.
“When they throw large sacks of drugs over, and if you have people on the other side of the wall, you don’t see them — they hit you on the head with 60 pounds of stuff? It’s over,” he said. “As crazy as that sounds, you need transparency through that wall.”