=600 Useful Arts.=
601 Philosophy.
602 Compends.
603 Dictionaries.
604 Essays.
605 Periodicals.
606 Societies.
607 Education.
608 Patents.
609 History.
=610 Medicine.=
611 Anatomy.
612 Physiology.
613 Hygiene.
614 Public health.
615 Materia medica and therapeutics.
616 Pathology, theory and practice.
617 Surgery and dentistry.
618 Obstetrics and sexual science.
619 Veterinary medicine.
=620 Engineering.=
621 Mechanical.
622 Topographical.
623 Military.
624 Bridge.
625 Road and railroad.
626 Canal.
627 Harbor.
628 Hydraulic and mining.
629 Instruments and field books.
=630 Agriculture.=
631 Soil and preparation.
632 Pests and hindrances.
633 Productions of the soil.
634 Fruits.
635 Garden.
636 Domestic animals.
637 Dairy.
638 Bees and silkworm.
639 Fishing, trapping.
=640 Domestic Economy.=
641 Cookery.
642 Confectionery.
643 Food and dining.
644 Fuel and lights.
645 Furniture.
646 Clothing and toilet.
647 Servants.
648 Laundry.
649 Nursery and sick-room.
=650 Communication, Commerce.=
651 Writing.
652 _Penmanship._
653 _Short hand._
654 Telegraphy.
655 Printing.
656 Navigation and transportation.
657 Book-keeping.
658 Business manuals.
659 Other.
=660 Chemical Technology.=
661 Chemicals.
662 Pyrotechnics.
663 Wines, liquors, and ales.
664 Sugar, salt, starch, etc.
665 Gas.
666 Glass.
667 Dyeing and bleaching.
668 Assaying.
669 Metallurgy.
=670 Manufactures.=
671 Metals.
672 _Iron._
673 Marble, stone, and brick.
674 Wood.
675 Leather and rubber.
676 Paper.
677 Textile fabrics.
678 _Cotton._
679 Other.
=680 Mechanic Trades.=
681 Watch and instrument-making.
682 Blacksmithing.
683 Lock and gun-making.
684 Carriage and cabinet-making.
685 Saddlery and shoe-making.
686 Book-binding.
687 Clothes-making.
688
689 Other.
=690 Building.=
691 Materials.
692 Plans and specifications.
693 Masonry.
694 Carpentry.
695 Slating and tiling.
696 Plumbing.
697 Warming and ventilation.
698 Painting, glazing, and paper-hanging.
699 Car and Ship-building.