Did William Coggeshall Save Lincoln's Life?

[Eva Elisabeth]

(09-16-2016 06:42 AM)Eva Elisabeth Wrote:  Re.: "According to Mary's telling, the incident occurred when Coggeshall and Lincoln transferred from the Harrisburg car to the Baltimore car where they were to be 'by themselves'" - I quote from Mary's account:

"Near Harrisburg, Pennsylvania, the presidential party was to change railroad cars and the train would be switched off to proceed to Baltimore. Lincoln and Coggeshall were the last to go out to the other car. 'As they neared the door, they heard a hissing sound and discovered a Hand Grenade just ready to explode. As Mr. Lincoln reached the door, Mr. Coggeshall grasped the shell and hurled it through the open window where it [had] been dropped into the car. As it struck beyond the tracks and exploded, no one was hurt.'"

Unless I missed it (I beg to apologize in case) I still miss someone (of those who think it possible) show up how the action was pulled through.
Assuming the trains were in motion - a horse rider approaching the train in full gallop? What does it need to make a "Hand Grenade just ready to explode"? Can you perform that while riding? From where/how if not from horeseback? Which other options were there, and how easy was it to throw such a ready-to-go item quickly through the window of a moving vehicle?

Thanks for any enlightenment!