Collectors call the top one a "pony" style insulator - usually used on local phone lines. The flat bottom on yours makes me think it might be on the older side (in the 1910-1920 area) but I'm not a porcelain expert and I'd want to see it in person before saying that for certain. Does it have any sort of marking? Generally, unmarked brown ponies, even with some age, don't generate a lot of collector interest.
The other one is a guy strain insulator, used on the guy wire supporting a pole, like in the photo here - it's below the crossarm, to the right:
Imagine if someone tried to support a pole using a solid wire anchored to the ground. It's not too hard to see that it would give the electricity a nice straight path to ground, creating shorts in the line. So the strain insulator (or Johnny ball) interrupted the guy wire. If you look at a modern-day pole, you'll probably see a porcelain strain-type insulator on the guy wire.
The glaze on yours looks like it might be older. Is it marked with a name of any type? Guy wire strains can be interesting, and there are lots of varieties, but most collectors are more interested in pin type insulators.
As usual, Bill has it all correct. The pony was made by Ohio Brass, a B inside an O, the O being difficult to see. Both are very common, about worthless to all except the most recent "Mud" (Porcelain) collector.
If the Illinois Glass Company was in operation in Detroit for only two years (1902-1903) it seems mighty coincidental to me they were located there at about the same time that James Vernor might have...
I'm still searching for specifics, but as near as I can determine at the moment, the Illinois Glass Company in Detroit appears to only have been in operation (at 220 Jefferson Ave.) for two years in...