Pocket sextant used by Victorian explorers and surveyors. Semi-functional, it has all the pieces needed to shoot the sun. A sextant defined latitude. A clock longitude. Defining the angle of Sun and Stars with the horizon was a way to navigate and survey.
The construction of the Metropolitan District Railway, Roofing over a cutting to form twin tunnels. The method of construction can clearly be seen, with five rings of brick arching being laid over two steel frames
Wassertorplatz in Kreuzberg. Construction works on the first subway line of Berlin. the are underway in this picture. Actually “subway” is a little misleading. as the line runs above earth for most of the time