"Storm glass" is a sealed glass tube containing a camphor-ethanol solution with aqueous NH4Cl and KNO3 solution. In 19th century England, the pattern and quantity of the crystals formed were observed and interpreted as a weather forecasting tool. In the present study; the pattern formation of the crystals in the storm glass solution was investigated by focusing on one parameter, such as the applied temperature. The growth patterns of the crystals in the storm glass solution were controlled using a directional growth apparatus and observed in situ as a function of the growth rate. Crystals grown in camphor ethanol solution were also observed for comparison. In addition, a replica of the storm glass attached to a temperature control system was constructed in order to examine the effect of the history of temperature variations on the crystals. X-ray diffraction patterns of the crystals were obtained to clarify the species of the crystals in the storm glass. (C) 2008 Elsevier B.V. All rights reserved.