Looks like the McMillan Reservoir.

The double back wheels indicate that it was destined for a very heavy work load during its lifetime. Does anyone know who might have absorbed W-W in the future?

The sipes on the outer right rear tire are pointing the opposite direction of the sipes on the other visible tires. Is it deliberate?

Employees of companies that bought this truck would have appreciated the all-weather cab and pneumatic tires. Driver comfort was just starting to be considered. Today, of course, it is well-known that a comfortable driver is a safer driver. I think I even see a brake drum in the front, although I find the lack of windshield wipers a bit odd. I love looking at photos of the primitive trucks that preceded this one, but shudder at their safety record.

Witt-Will was in business in Washington, D.C. from 1916 to 1932, according to American Truck Spotter's Guide by Tad Burness.

Once again I'm impressed with the amount of detail captured by these large-aspect cameras. Little things like the push-on grease fitting on the steering link and the front tire valve stem, details of the multi-piece split rims and the front spring shackles.

The little evenly-spaced holes in that radiator give away that it's a honeycomb type -- every one of those holes is a long copper tube with specially flared ends painstakingly soldered to its neighbors, expensive to build and pricey to fix even then, astronomical now.

Now that's a nice looking truck. Pneumatic tires!

Note the silvery lever coming out of the steering column. That's probably the throttle, or possibly the spark advance. These were separate controls back then.