Mary A. Delaney was an American inventor. Very little is known about her life, other than she received a patent May 12, 1908, for her invention of the retractable dog leash. Here is how Mary Delaney describes why she created her invention:
“It is usually desirable that the dog should have a certain freedom in running about, but it is difficult to prevent the animal from running on the wrong side of lamp posts or pedestrians, thus causing much annoyance to the owner, who is constantly required to adjust the length of the leash in her hand, and frequently the lease is dropped and the dog permitted to run away. The objects of the present invention are to obviate and overcome all these difficulties and annoyances due to the usual form of leash, and prevent the leash from becoming tangled as the dog runs about.”
Limited information about Mary A. Delaney may be found at the following website:
http://www.slate.com/articles/technology/history_of_innovation/2014/06/mary_a_delaney_inventor_of_the_first_retractable_dog_leash.html
https://www.google.com/patents/US887072