zacatlán has a reputation for tinkerers, including abraham trejo, who created his own car and gabriel melecio, who invented a machine to toast coffee beans. however, the best known of these is alberto olvera hernandez, who founded the centenario clock company. olvera hernandez grew up on a farm outside of zacatlán called coyotepec. he became interested in clocks and watches after taking apart a broken clock at his home. he was self-taught, even making the needed tools himself with only the materials and other items found on the farm. he began to build and sell clocks in 1909 and created his first monumental clock in 1918, when he was seventeen years old. this prompted the founding the first clock factory in latin america, centenario, which specialized in monumental clocks, located on calle nigromante near the town center. its monumental clocks have been installed in buildings, parks, plazas and commercial centers in mexico and other countries. one of the first clocks produced by olvera hernández is over eighty years old and still functions in a church bell tower in chignahuapan. there are examples of centenario clocks in most parts of mexico today. one of these clocks is in tulantepec, hidalgo, and plays the mexican national anthem in the morning and evening and his distinct melodies for each quarter-hour. it is not electric but completely mechanical using counterweights. however, the factory's most famous piece is the flower clock in the zacatlán main square. today, the centenario factory employs about fifty people and is open to visits by the public. in the upper part of the building, there is a clock museum inaugurated in 1993 and dedicated to the founder. it contains original and reproduction timepieces over history in the world. they include timepieces using water, the sun, sand and candles. one is a figure of merlin, whose arms indicate the time but only for 12 hours during the day. at the end of the day, his arms lower to “rest.”