The Science of Ice Formation--Preparing the Ice Field for the Harvest--Getting Rid of Snow--Sudden Thaws and How to Remedy Their Damage--Tools and Implements Used--Thickness of Ice--Care of Ice Tools--Filling the Ice House--Closing it up and Caring for It--Shipping Ice from the Field. With the advent of a sharp freeze, attention is directed to the ice field, from which a harvest is hoped for at no distant day. The purification of the water has been given attention before this time, together with all preliminaries relating to the plant in its various and complex features. The weather now determines the lot of the ice dealer. As the cold breezes whistle over the water, stirring it into ripples, and breaking its surface into waves, a wonderful change is rapidly transforming its liquid pearls into flinty diamonds. Gradually the heat in the water is radiated into the air. As fast as the surface water is cooled, it is condensed, and sinks to the bottom, its place being taken by the warmer and lighter water from beneath. Gradually the entire mass reaches the point of maximum density, at 39½° F. Below this temperature, until it reaches 31° F., water expands as it is cooled. Now the surface water no longer sinks as it grows colder, being rendered lighter by expansion than the water beneath. Upon reaching 32°, convection, or freezing, takes place, and the surface assumes the solid form. CARE OF THE ICE FIELD.--From this time until the crop is stored in the ice house, the ice dealer devotes his energies to the care of the ice field. Special situations develop special duties and requirements, which the alert dealer studies with care. If the ice is on a running stream, the possible pollution of its higher levels will be carefully guarded against, and also all rubbish removed from the surface of the field. Sticks and stones bedded in the ice hinder the work and damage the keen edges of the cutting tools. Motion in the water is necessary to promote the growth of the ice, and, when the ice is sufficiently heavy, traveling over the surface, or other jarring, is beneficial. It has been found that where a roadway has been opened across an ice field, and the travel over it considerable, the ice was thicker along the roadway than at other places on the field. On inclosed lakes or mill ponds, a gentle current induced in the water promotes the growth of the ice materially. The air is expelled from the water during freezing, if opportunity is found for it to do so. Unless this is done, the ice is cloudy. Agitation of the water assists the escape of the air; hence it is that ice from running streams is usually clearer and more brilliant than pond or lake ice. An outlet afforded to the land-locked ponds and lakes is often beneficial during ice-making weather. Too rapid a current, however, will retard growth, and a gentle motion diffused over the entire field produces the best results.