1906 and then 1907 fire dept vehicles for comparison, and the jump from horse to motor vehicle

the two from the above are in the next photo,

but I don't see the above vehicle in the below group. It has what appear to be clinchers or chains on the back tires. That's odd, but the roads were dirt back then though...

https://calisphere.org/collections/26397/?q=&rq=&rq=&rq=&rq=&rq=&rq=&rq=&sort=a&start=3816