If the 300 had been sent, what good would it have done?
In 21 hours of industrious fighting, Jameson's 530 men, with 8 Maxims, 3 cannon, and 145,000 rounds of ammunition, killed an aggregate of 1.
Boer.

These statistics show that a reinforcement of 300 Johannesburgers, armed merely with muskets, would have killed, at the outside, only a little over a half of another Boer.

This would not have saved the day.
It would not even have seriously affected the general result.

The figures show clearly, and with mathematical violence, that the only way to save Jameson, or even give him a fair and equal chance with the enemy, was for Johannesburg to send him 240 Maxims, 90 cannon, 600 carloads of ammunition, and 240,000 men.

Johannesburg was not in a position to do this.