What is the significance of the architecture of the buildings of Jantar-Mantar and Safdar's Tomb in the history of modern Indian architecture? Discuss.

The Jantar Mantar or Delhi Observatory was built by Maharaja Jai Singh of Jaipur in 1710 AD. He was a keen astronomer who studied Hindu, Muslim and European astronomical works. He found that the astronomical tables then being used by the pandits were defective, so that the actual times of eclipses etc., were different from the times stated in the tables. He thought that this was due to the fact that the existing instruments were small and faulty. He therefore built large instruments of his own invention. Thus this observatory was built by him in Delhi similar to those in Jaipur, Ujjain, Benaras and Mathura. As a result of his work, the tables were corrected and the predictions were now correct.
Safdarjang’s Tomb was built in 1753-54 by the Nawab of Awadh for his father Safdarjang. The materials used in the buildings of the Tomb are of poor quality.
When Safdarjang was alive, he used it as his residence. After his death, the rooms round the Tomb were used for entertainment and not for residence. This is the reason why the pavilions were built. This complex also housed a madarsa and even today, it is known as Safdarjang Madarsa and not as Safdarjang Maqbara. The Nawab of Awadh failed to get the building constructed by craftsmen who built the Mughal buildings and did not use the material suitable for Delhi. It is why the tomb is not in good condition.