simple transistor question

I am reading through an online tutorial and something is confusing me on the subject of transistors.

On this webpage



on the light bulb, transistor circuit halfway down the page, the base of the transistor is connected to the positive side of the battery. But on the examples below such as the solar panel, the base of the transistor is connected to the negative side of the battery.

Has the author made a mistake with the diagram or am I just missing something?

Thanks

Mark S.

The three examples are fed from an external positive source, they aren't connected to the negative.

Thanks Nigel, i figured it out after closer inspection.