The observatory , officially " Her Majesty 's Magnetical and Meteorological Observatory at Toronto " , was completed the following year . It consisted of two log buildings , one for the magnetic instruments and the other a smaller semi @-@ buried building nearby for " experimental determinations " . The north end of the main building was connected to a small conical dome which contained a theodolite used to make astronomical measurements for the accurate determination of the local time . The buildings was constructed with as little metal as possible ; when metal was required , non @-@ magnetic materials such as brass or copper was used . A small barracks was built nearby to house the crew .