Sorting Numerics

[Liquid Metal]

What is the easiest way to sort this properly?

H 1.txt
H 10.txt
H 100.txt
H 1000.txt
H 2.txt
H 3.txt
H 4.txt
H 5.txt


Want it to be like this.
H 1.txt
H 2.txt
H 3.txt
H 4.txt
H 5.txt
H 10.txt
H 100.txt
H 1000.txt