Changing times!
New post 100 years ago probably meant you had a posting to a new position, perhaps in the service!
New post 50 years ago probably translated as another delivery into your mail box (snail mail that is, althought nobody in that time would be familiar with that term!!)
New post now means that you are about to create a new message on your blog.
Blog of course comes from log and
100 years ago the log was probably referring to a ship's record,
50 years ago, probably pertained to warming the fire,
whereas right now, it's our way to share details of our travels, without cutting down trees, and a [b]log can still warm the hearts of those who gather close :)