Do not let the rubber strap contact the oil in the Thiele tube or you will lose your sample and have to start over. If the identity is correct, the melting point should not significantly change. If it is incorrect, the melting point will change substantially and will occur over a much broader range. Glass bells have been created already.
Procedure is to invert a capillary tube in a glass bell containing the liquid to be tested.
You will be given two known liquids and one unknowns. Determine the boiling point by using three trials on each sample and record the average for each.