mass is inedible. Many animals weakened by the long drive died in transit, further increasing the per-unit shipping cost. Swift's solution to these problems was to devise a method to ship dressed meats from his packing plant in Chicago to the East. Advent of the refrigerator car A number of attempts were made during the mid-19th century to ship agricultural products via rail car. As early as 1842 the Western Railroad of Massachusetts was reported in the June 15 edition of the Boston Traveler to be experimenting with innovative freight car designs capable of carrying all types of perishable goods without spoilage. The first known refrigerated boxcar or "reefer" entered service on the Northern Railroad (or NRNY, which became part of the Rutland Railroad) in June 1851. This "icebox on wheels" was a limited success in that it was only able to function in cold weather. That same year, the Ogdensburg and Lake Champlain Railroad (O&LC) began shipping butter to Boston in purpose-built freight cars, utilizing ice to cool the contents. The first consignment of dressed beef to leave the Chicago stockyards was in 1857, and was carried in ordinary boxcars retrofitted with bins filled with ice. Placing the meat directly against ice resulted in discoloration and affected the taste, hence proved impractical. During the same period Swift experimented by moving cut meat using a string of ten boxcars which ran with their doors removed, and made a few test shipments to New York City during the winter months over the Grand Trunk Railway (GTR). The method proved too limited to be practical. Detroit's William Davis patented a refrigerator car that employed metal racks to suspend the carcasses above a frozen mixture of ice and salt. He sold the design in 1868 to George H. Hammond, a Detroit meat-packer, who built a set of cars to transport his products to Boston using ice from the Great Lakes for cooling. The loads had the unfortunate tendency of swinging to one side when the car entered a curve at high speed, and the use of the units was discontinued after several derailments. In 1878 Swift hired engineer Andrew Chase to design a ventilated car that was well-insulated, and positioned the ice in a compartment at the top of the car, allowing the chilled air to flow naturally downward. The meat was packed tightly at the bottom of the car to keep the