Here's a very early porcelain insulator made with the bold embossed TE (short for Telegrafo del Estado) and arrow to designate the official State Telegraph line. The arrow is associated with early turn of the century military telegraph lines. Insulator also has unusual notches- two opposite the wire groove on the crown and two on the lower wire ridge likely designed to improve grip of the tie-wire.

This example was recovered in Chile but was probably made as a special order export item from England. Thanks!