Other classical names for dildo include - godemiche, and penis coriaceus, which means leather penis, as used in Lysistrata, and hapax legomenon in the Classical Greek literature. The word "dildo" also refers to the phallus-shaped peg used to lock an oar in position on a small boat, which was inserted into a hole on the side of the boat, and is very similar in shape to the modern sex toy. One suggestion is that the modern dildo takes its name from this, although it has also been suggested that it could be a corruption of the Italian word "diletto" meaning, "delight". Dildo in Latin means to "open wide”. The world's oldest known dildo is a siltstone 20-centimeter phallus found in Germany and is thought to be from the Upper Palaeolithic period 30,000 years ago. Archaeological findings show that ancient Egyptians used dildos 2,500 years ago. Dildos were also used by ancient Greeks. A vase depicting a woman using a dildo on herself was thought to have been made in the fifth century B.C. Another ancient Greek vase from around the 6th century B.C. depicts a scene in which a women bends over giving a man a blowjob, while another man is inserting a dildo into her anus. In addition, dildos are represented throughout history in erotic painting, and were often quite beautifully designed, being works of art themselves.The first dildos were made of stone, tar, wood and other materials that could be shaped as a penis and were firm enough to be used as penetrative sex toys. Chinese women in the 15th century used dildos made of lacquered wood with a textured surface. Dildos have been found in China that date back as early as the New Stone Age, more than 12,000 years ago. A tomb recently uncovered in China contained seven cast bronze dildo’s which were thought to be used by palace maids on sexually deprived imperial concubines or aristocratic women during the Han Dynasty. Also discovered in ancient China are hand crafted dildo’s made of wood, jade, and ivory, which double as works of art. In Ancient Greece women enjoyed using olisbos, which were phallic shaped objects made of wood or leather. Back in those days, olive oil wasn't just a staple of the Greek diet, it doubled as the best lubricant available. The Greeks believed that a lack of sperm caused hysteria, or a wandering uterus, in women. Greek men who left home for long periods of time to fight in wars often gave their wives olisbos to prevent hysteria, a link that lasted well into the 20th century. Celtic women danced beneath the full moon in the freshly plowed fields, sometimes even ritually masturbating themselves with short-handled brooms in order to bring fertility to the earth before planting. Sometimes they would coat the broomstick with psychoactive drugs! The word ‘dildo’ first appeared in English print in 1610. By the time of the Renaissance, the dildo had become an art form. Members of the upper classes had dildos custom made from silver, ivory, and other precious materials. Rubber dildos, usually incorporating a steel spring for stiffness, became available in the 1940’s. This was a less than satisfactory arrangement because of the potential for serious injury from cuts from the spring when the rubber finally cracked, and came apart. Later, PVC dildos with a softer PVC filler became popular. Most of the inexpensive dildos sold today are made this way. PVC and jelly-rubber toys should be avoided because they contain unsafe phthalates, softeners added to many plastics that are also found in some jewelry, food containers, and other soft rubber toys. In the 1990’s, silicone rubber dildos became more popular, a trend that has continued as the prices have lowered. These are easier to clean and do not have the characteristic plastic aroma of PVC. Silicone holds body heat well, and is also a robust material, especially when compared to the cheap, unsafe jelly rubber that many dildos are made of. High-end, chrome plated steel dildos are very popular. Some users prefer them because of their hardness, firmness, durability, and low friction, especially when used in conjunction with lubricant. Because they are heavy, they can be used to exercise vaginal PC muscles. A steel dildo may be warmed or cooled in water before use to elicit a range of temperature sensations. It may also retain body heat of the user. Because of its polished nonporous surface it is easy to clean. Glass dildos have similar features to steel ones. Glass toys are solid, not hollow, and usually made of Pyrex or borosilicate glass, although this may vary depending on manufacturer. Like steel, glass toys may be used to apply firmer pressure than silicone can to a female's G-spot.