David, This cancel is from a Barry Postal Supply Co. (aka Barry Rapid Cancel Machine Co.) who had a plant in Oswego, NY and produced canceling machines from 1895-1909. The cancel has an open rectangular dial (where the city and date is) and "jagged" or "lightening bolt" diagonal killer bars. There is a place for a machine number slug but no slug is installed (which is not uncommon).
This type of cancel in very common with straight line diagonal killer bars but this is the first example I have seen with the jagged diagonal bars. I have seen Barry cancels with jagged horizontal killer bars (I thought I had a scan of one but was unable to find it. I will post if found)
Below is an example of a similar Barry cancel with the straight diagonal line killer bars

Here are a couple of my favorite Barry cancels

Chicago "Mail Delayed Train Late"

The ornate Oswego, NY