Country vegetable soup

Some background. This is the very first recipe in my mother's family recipe book, a red, leatherbound, hardback volume, simple entitled on the cover "Recipes". Inside, the title page reads: "Walker's PRIVATE RECIPE BOOK", followed by "A HANDY BOOK FOR THE HOUSEWIFE" and then the publishers: "JOHN WALKER & Co. LTD., 12, HANOVER SQUARE, LONDON, W.I." All the addresses where my mother lived in her married - and post-married - life are there, most in her handwriting, some in mine.

There is then a list of the various sections of the book:

Soups.
Fish.
Entrees.
Meat, Game and Poultry.
Vegetables and Sauces.
Omelets [sic], Puddings and Sweets. (My mother has added PASTA here.)
Cakes and Pastry.
Jellies, Creams, Ices, etc.

This first recipe for "Country vegetable soup" appears to have been written before she was married, though, because it is signed in red ink in her maiden name: "A Weiss (Patent pending)". That is, unless the "A Weiss" refers to her brother, which I think is a little unlikely but not impossible. This is probably a soup of which he would approve and he's a scientist so "Patent pending" sounds like him.

Here are the ingredients:
3 large potatoes
4 large carrots
4 large tomatoes
2 large onions
3 pints stock
mixed herbs
pepper
salt

The method:

Heat stock and add coarsly grated potato, carrot and onion. Bring to boil and allow to simmer for 1/2 hour. Add sliced tomatoes and mixed herbs. Any suitable leftovers may be added.

There's much more to be written on the topic of soup - but my only caveat would be the words "Any suitable leftovers may be added". I would want to add the words: "if you're an expert", because this simple soup could very very easily be ruined. I think I might also want to be careful about the "mixed herbs". For another day.