(a) Lamp post

1. In Indus Valley archaeologists have discovered lamp posts at intervals. This suggests the existence of street lights.

2. Today street lighting commonly uses high intensity discharge lamps often HPS—high pressure sodium lamps.

(b) Burnt bricks

(i) In Harappan Civilization, the houses were built using baked bricks and ’mortar. Sun dried bricks were also used, Most of the bricks were of uniform size. They used the burnt bricks which were strong, hard, durable, resistant to fire and would not dissolve in water.

(ii) Even at present, brick is the most basic and favoured material for common construction through out the world. Nowadays bricks are available in different sizes and shapes. Kiln burnt bricks are used.

(c) Underground drainage system

(i) In Indus Civilization, they had covered drains. The drains were covered with slabs or bricks. Each drain had a gentle slope. Manholes were provided at regular intervals to clear the drain.

(ii) At present our cities and town are so populated and congested that conducting any infrastructural improvement over ground or underground is becoming difficult.

(d) Weights and measurement,

(i) Indus people used standardised weights and measures. They used sticks with marks to measure length.

(ii) In the modem world, we use electronic weighing machine to have accuracy in weighing.

Floor scales and Platform scales are used in industries and small scale industries respectively.

(e) Dockyard

(i) A naval dockyard has been discovered in Lothal in Gujarath. It shows the maritime activities of the Indus people.

(ii) In modem days, there are may well developed ports in India. To quote a few, Chennai port, Kandla port, Tuticorin port, Cochin port, Paradip port etc.