This recalls a method of shipping pianos in refrigerator cars. The instruments are carefully brought to the temperature of the car, which is maintained at about zero, Centigrade. When the pianos arrive at their destination they are slowly warmed to the temperature of common air. No matter how long they have been cold, they suffer no hurt; for it is not cold, or moderate elevation of temperature, that does harm so much as uneasy fluctuations from one to the other. Loose Cards Replace Books. When one visits a public library, the title of a particular book is found in the catalogue in a moment. Every book as acquired has its title written on a card, and thousands of such cards are placed in alphabetical order, just like the words in a dictionary. A thousand cards or so begin with “A,” and are placed in a drawer marked “A,” which stands first in the case, and so with the rest. There is always room to spare in each drawer, so that when a card for a new book comes in there is space for it. It was a happy thought of a Dutch inventor when he thus made an index which can always be alphabetical, easily added to or subtracted from, simply because its leaves are mere cards with the binding of a common index omitted. In public libraries the catalogue-cards are of standard sizes, so also are the drawers in which these are disposed. In fact library-furniture of all kinds is to-day thoroughly standardized in its styles and dimensions, making it easy to fit up or to extend a library whether public or private. The use of cards, or slips for like purposes, has passed from the library to the business office, the study, the housekeeper’s desk. Merchants keep their customers’ names on this plan, so as to send them price lists from time to time. Depositors in banks, policy-holders in assurance companies, tenants of real estate in cities, members of clubs, are all recorded in this simple and accessible fashion. Some great manufacturing houses receive a million letters in a twelvemonth; an adaptation of the card-index makes any single letter accessible in half a minute at most. To an extent which steadily grows, the same plan is ousting the old-fashioned ledgers from our offices; in their stead we are now using series of movable leaves which are removed when filled, giving place to new leaves in an unbroken round. [Illustration: Notes on loose cards in alphabetical order.]