Recent and ancient history would surround travellers in any subway built in Greater Winnipeg.

Recent history would highlight an assortment of water, gas, and sewer mains, telephone cables and anything put underground by man.

Ancient history is the soil strata.

(The) roof of the subway, says engineer Norman Wilson, would have to be about 13 feet under the surface. Rail level would be 25 to 35 feet down.

Above their heads, passengers would have city dust and surface soil. Then there would be yellow clay, gradually running into brown clay to a depth of about 13 feet.

This is the former bottom of old Lake Agassiz, scraped out during the ice age. It is the clay that has been the curse of building owners. Subject to great moisture changes, it causes cracking and shifting of city foundations.

Then there is blue clay, very moist but impervious to passage of water. It is usually about 40 feet thick. Beneath that is a thin layer of white clay.

For about 10 feet below the white clay there is a glacial deposit composed of boulders of granite and limestone in a mixture of sand, glacial clay and ground-up limestone dust, all impervious.

Locally, it is referred to as "hardpan." It is easily excavated, says Mr. Wilson, though not as easily as the strata above.

Next comes an 18-inch layer of decomposed limestone. And then there is bedrock of hard limestone averaging 50 to 75 feet below prairie level.

If the travellers could see into the past, they would have to look up to catch Indians, buffalo and the running fight at Seven Oaks.