vintage city of chicago depression era freestanding no parking by police order street sign. the stationary sign contains a weighted cast iron base with manufacturer markings in the form of embossed lettering. the double-sided circular sign with incised letter has a nicely weathered finish with the original red & white somewhat intact. manufactured by lyle signs. measures 50 x 12 inches. in 1900, the lyle culvert company started making metal culverts at lyle, minnesota. a year later, in 1901, the company moved to minneapolis, mn. in 1912, two engineers with the culvert company, the fraser brothers, designed, developed and patented some sign making machines -- hence the birth of lyle sign division of the lyle culvert company. the machines were built on the pantagraph principle with messages carved or routed approximately 1/16" deep in heavy (12 gauge) steel. for the next 21 years, traffic, park, parkway and street name signs were produced by this carved-in-process. in 1928, the sign division was separated from the culvert company. lyle signs, incorporated was established as a separate corporation. in 1933, lyle bought its first embossing press, designed and developed male and female dies to emboss complete sign messages and strengthen borders on 14, 16 and 18 gauge metal, all in one operation. carved-in process signs were still produced because of their extreme longevity, but as years passed, costs of labor (carving one letter at a time) made prices prohibitive. there are, however, carved-in process street name signs still in use in many cities, after 40 or 50 years of service, with only minimum refinishing maintenance costs involved. the demand for embossed message signs gain popularity from 1933 to the start of world war ii, at which time the use of metal for sign purposes was restricted by federal regulations. during the war years, lyle signs used its facilities in the manufacture of defense items, primarily stamping for the aircraft industry. in 1945, federal restrictions on the use of metal for sign purposes was lifted and lyle was back to making traffic and street name signs.