Here is a page of summer clothing styles for Victorian boys for the year 1900.

Very manly is this small laddie. He is stylishly clad in a Norfolk jacket and knickerbockers which bulge in true golfer fashion at the knees.

A simple, easily constructed and absolutely comfortable outfit for a small boy is that shown below. Both blouse and trousers are made of brown duck – which wears like iron and launders as good as new – just the material required for the clothing of an active urchin with a proclivity for dirt and destruction.

This young midshipman is most nautically clad in a middy jacket and vest, and sailor trousers with widely flapping legs.

This somewhat more dressy costume would be appropriate for afternoon, and at the same time is not so fine that the youngster who wears it would be uncomfortably hampered.

And here is the last bit of the magazine article.

The pages are from the July 1900 issue of The Designer magazine.
Click on images to enlarge.