PH1663 Aneroid Barometer PH1564 Reading Telescope PH1665 Hand Dynamo, AC and DC PH1566 Steam Engine PH1667 Steam Engine PH1568 Gas Engine PH1669 Solar Cooker PH1571 Sectional Working Model of 2 Stroke Petrol Engine PH1672 Sectional Working Model of 4 Stroke Petrol Engine PH1573 Sectional Working Model of 2 Stroke Diesel Engine PH1674 Sectional Working Model of 4 Stroke Diesel Engine PH1575 Demonstration Electric Bell PH1676 Traffic Lights PH1577 Bramah Hydraulic Press PH1678 Kinetic Theory Model PH1579 Drawing Board PH1680 Black Board Instrument Box PH1581 Overhead Projector PH1682 Slide Projectors Standard Design