That year Malling-Hansen developed a fast speed writing machine to be used for stenography, called the Takygraf.

Malling-Hansen was also the first person to discover the unique possibilities of blue carbon paper, and developed a copying technique he called the Xerografi.

[2] Malling-Hansen implemented a new pedagogical speech method of reading lips for the group called the not originally deaf; those who had a limited hearing ability and could also speak.

The sign method was still used when teaching the group called the originally deaf, those who had no hearing ability and no language, and the mentally challenged.

This was in a very early stage of the educational system, and the understanding of children's needs to play and to relax was not yet developed.

Children were required to get up at 5 o'clock in the morning, and in addition to the teaching they had to work in the workshops of the school in late hours.

The death rate was high, and in the first period of the Institute, from 1824 until 1839, one-third of all the children died, mostly of lung diseases.

Malling-Hansen understood that the main reason for the lung diseases, was the lack of space in the school - there were too many children in a too small area.

In 1890, shortly before his death, he held a lecture about the development of the education of the deaf-mutes at an inter-Nordic conference in Copenhagen.

After she and the twin girls died, Malling-Hansen remarried in 1880, to a woman he knew from his youth, Anna Steenstrup.