The idea of monitoring environmental fluctuations at alleged haunted locations dates back to at least the early 1920's, when serious paranormal investigators such as Harry Price began applying the principals of scientific method to spontaneous paranormal investigations in the field. Investigators have long speculated that paranormal activity somehow alters the ambient environment, be it in the form of static electricity, humidity, temperature or background radiation. If serious investigators used environmental montoring devices to establish baselines during their investigations, anomalous fluctuations could be observed and documented. Accumulating such data over a period of time could help identify patterns that might lead to possible explantions for paranormal activity. Unfortunately the technology of the early 20th century was not only unwieldy, it was outrageously expensive, so such information is extremely scarce.