80 Sloan's Architectural Review and Builders' Journal. [July, sounding the chime in the house, sounds one over his head. Thus warned he comes up to the house to leave what he has brought, and to take away the let- ters ready for mailing. " My electric door-keeper then (says Houdin) leaves me nothing to be desired. His service is most exact ; his fidelity is thoroughly proven ; his discretion is unequalled ; and. as to his salary, I doubt the possi- bility of obtaining an equal service for a smaller remuneration." The study clock transmits the time to two dial plates. One, placed upon the front of the house, gives the hour of the day to the neighborhood; the other, fastened to the gardener's lodge, facing the house, gives the time to its inmates. Several smaller dials, operated similarly, are placed in the various apartments. They all, however, have but a single striking part, but this is powerful enough to be heard over the entire village. Upon the top of the house is a tower contain- ing a bell on which the hours of meals are announced. Below this is a train of wheel-work to raise the hammer. To avoid the necessity of winding up the weight every day, an automatic arrange- ment is employed, which utilizes a force ordinarily lost. Between the kitchen, situated upon the ground-floor, and the clock-work in the garret, there is a con- trivance so arranged that the servants, in going to and fro, about their work, wind up the weight, without being con- scious of it. An electric current set in motion by the study-regulator, raises the detent, and permits the number of strokes indicated by the dial. This manner of distributing the time from the study, Houdin finds very useful. When, for any reason, he wishes the meals hurried or retarded, he presses a secret key, and the time upon all the dials is altered to suit his convenience. The cook finds often that the time passes very rapidly ; while a quarter of an hour or more, not otherwise attainable, is gained by M. Houdin. Every morning this clock sends, at different hours, electric impulses to awaken three persons, the first of whom is the gardener. But, in addition, the apparatus forces them to rise, by con- tinuing to sound until the circuit is broken by moving a small key placed at the further end of the room. To do this the sleeper must rise, and then the object sought is accomplished. The poor gar- dener is almost tormented by this elec- tricity. The greenhouse is so arranged that he cannot raise its temperature above ten degrees Centigrade (50 de- grees Fahrenheit), or let it fall below thirty degrees C. (37 degrees F.), with- out a record in the study. The next morning Houdin says to him, " Jean, you had too much heat last night ; you will scorch my geraniums ;" or, "Jean, you are in danger of freezing my orange trees ; the thermometer descended to three degrees below zero (27 degrees F.) last night." Jean scratches his head and says nothing, but he evidently re- gards Houdin as a sorcerer. — Yale Col- lege Courant. Pigments in Madder. — Taking ad- vantage of M. Schutzenberger's investi- gation of madder, which was proved to contain five pigments, M. Martin has lately perfected and patented in France a process for transforming four of them into the only one (alazarine) j'ielding an unalterable dye. The several coloring matters are first dissolved in concen- trated sulphuric acid, and then zinc is added. The reaction is accelerated by the use of powdered zinc and the appli- cation of heat ; when it is completed the mass is diluted with water, and the abundant precipitate is the required dye, which, after being washed with water, is readj r for use. Thus orange- madder, purpurine, pseudo-purpuriue, and xantho-purpurine are transformed into alazarine. This process for making available all the coloring matter in mad- der seems to be important in a pecuni- ary, as well as scientific, point of view.
