The answer is ANDREW CARNEGIE The corresponding square is PENNSYLVANIA RAILROAD by Ray Jones This is the "Tree" runaround Most of the trees at MIT are numbered (and barcoded). Each numbered tree has a little plaque with its common name, latin name, barcode, and number. This runaround is a "nature walk", going from tree to tree, recording their numbers and letters from the names. Most of the trees are pretty near each other (so it's not hard to find the next tree if you've found the current one). There are a few jumps, but those are marked by special symbols in the string of numbers: the great sail, a street crossing, an arrow going into a tunnel (under building 9), and a hazard symbol (matching one visible from the tree just before it). The trees with names are listed below. The clue phrase "under the last tree" is taken from letters on the first few trees. Great Sail 760 Norway Maple Acer platanoides 757 18 u Thornless Honeylocust Gleditsia triacanthos inermis 756 5 n Thornless Honeylocust Gleditsia triacanthos inermis 755 24 d Thornless Honeylocust Gleditsia triacanthos inermis 753 13 e Thornless Honeylocust Gleditsia triacanthos inermis 752 19 r Flowering Dogwood Cornus florida 751 1 t Thornless Honeylocust Gleditsia triacanthos inermis 750 10 h Thornless Honeylocust Gleditsia triacanthos inermis 747 10 e American Yellowood Cladrastis kentuckea 746 11 l American Yellowood Cladrastis kentuckea 742 5 a Pin Oak Quercus palustris PinOa kQuer cuspa lustr is 741 13 s Pin Oak Quercus palustris 740 19 t Pin Oak Quercus palustris 739 19 t Pin Oak Quercus palustris 738 10 r Pin Oak Quercus palustris 737 9 e Pin Oak Quercus palustris 709 18 e Flowering Crabapple Malus species 706 Hawthorn Crataegus species (?) 704 11 c Pin Oak Quercus palustris 702 7 i Flowering Dogwood Cornus florida 699 27 i Flowering Dogwood Cornus florida 698 Kousa Dogwood Cornus kousa 697 Sourwood Oxydendron arboreum (CHECK) 694 Flowering Dogwood Cornus florida 695 Pin Oak Quercus palustris 693 Flowering Dogwood Cornus florida 692 Pin Oak Quercus palustris 689 Flowering Crabapple Malus species 687 16 l Pin Oak Quercus palustris 658 21 v Japanese Zelkova Zelkova serrata 660 22 i Hawthorn Crataegus species (?) 661 18 i European Linden Tilia xeuropaea 664 Katsuratree Cercidiphyllum japonicum 666 15 c Katsuratree Cercidiphyllum japonicum 668 20 x European Linden Tilia xeuropaea 669 9 l European Linden Tilia xeuropaea 670 European Linden Tilia xeuropaea 671 Japanese Zelkova Zelkova serrata 673 Japanese Zelkova Zelkova serrata 674 English Elm Ulmus procera (?) 683 Pin Oak Quercus palustris 682 Pin Oak Quercus palustris 681 Pin Oak Quercus palustris (???) 680 11 c Red Oak Quercus rubra 679 9 l Sugar Maple Acer saccharum (?) 1613 21 i Pin Oak Quercus palustris 1614 Flowering Crabapple Malus species 1615 Flowering Crabapple Malus species 1616 Norway Maple Acer platanoides (?) 1617 Pin Oak Quercus palustris 629 Red Oak Quercus rubra 631 Pin Oak Quercus palustris 627 English Elm Ulmus Procera 633 11 c Pin Oak Quercus palustris 625 18 l Japanese Zelkova Zelkova serrata 635 Pin Oak Quercus palustris 623 American Elm Ulmus americana 637 Pin Oak Quercus palustris 622 Japanese Zelkova Zelkova serrata 620 European Linden Tilia xeuropaea 621 Japanese Zelkova Zelkova serrata 608 Japanese Zelkova Zelkova serrata 607 Japanese Zelkova Zelkova serrata 603 Pin Oak Quercus palustris 602 Pin Oak Quercus palustris 599 11 c Pin Oak Quercus palustris 598 10 x Sourwood Oxydendron arboreum 597 16 l Pin Oak Quercus palustris 594 2 i Pin Oak Quercus palustris 593 Pin Oak Quercus palustris 579 Pin Oak Quercus palustris 578 Pin Oak Quercus palustris 577 Pin Oak Quercus palustris 576 Pin Oak Quercus palustris 590 Scholar-tree Sophora japonica 589 Flowering Crabapple Malus species 568 Kwanzan Cherry Prunus serrulata 'Kwansan' 571 Pin Oak Quercus palustris 572 Pin Oak Quercus palustris 573 Red Oak Quercus rubra (CHECK) 570 11 c Pin Oak Quercus palustris 586 30 i Pyramidal Japanese Yew Taxus cuspidata 'Capitata' 585 6 i Pyramidal Japanese Yew Taxus cuspidata 'Capitata' 588 Pin Oak Quercus palustris (CHECK) 584 Pyramidal Japanese Yew Taxus cuspidata 'Capitata' 583 Pyramidal Japanese Yew Taxus cuspidata 'Capitata' 582 Cherry Prunus species 581 26 c Pyramidal Japanese Yew Taxus cuspidata 'Capitata' 580 24 l Flowering Dogwood Cornus florida 566 2 i Pin Oak Quercus palustris 1690 Pin Oak Quercus palustris 1689 Pin Oak Quercus palustris Cross Street 1730 Japanese Zelkova Zelkova serrata 1734 Red Oak Quercus rubra 1735 Pin Oak Quercus palustris 1737 11 c Red Oak Quercus rubra 1744 24 x London Planetree Platanus xacerifolia 1742 24 x London Planetree Platanus xacerifolia 1743 24 x London Planetree Platanus xacerifolia 1739 29 i London Planetree Platanus xacerifolia 1752 European Beech Fagus sylvatica 1754 European Beech Fagus sylvatica 1756 European Beech Fagus sylvatica 1759 Katsuratree Cercidiphyllum japonica 1762 European Hornbeam Carpinus betulus 1763 Eastern White Pine Pinus strobus 1764 Red-leaf Japanese Maple Acer palmatum 'Atropurpureum' 1768 Eastern White Pine 1767 Flowering Dogwood Cornus florida 1766 17 c Flowering Dogwood Cornus florida 1716 24 l Flowering Dogwood Cornus florida 1715 Eastern White Pine 1717 Red Oak Quercus rubra 1714 Red Pine Pinus resinosa 1713 Red Pine Pinus resinosa 1711 Red Pine Pinus resinosa 1710 Red Pine Pinus resinosa 1709 Red Pine Pinus resinosa 1699 Red Pine Pinus resinosa 1700 Red Pine Pinus resinosa 1698 10 c Pin Oak Quercus palustris 1697 2 i Pin Oak Quercus palustris 1696 2 i Pin Oak Quercus palustris 1695 25 i Thornless Honeylocust Gleditsia triacanthos inermis Cross Street 1657 Pin Oak Quercus palustris 1658 Pin Oak Quercus palustris 1659 Pin Oak Quercus palustris 1656 Flowering Crabapple Malus species 1655 Pyramidal Japanese Yew Taxus cuspidata 'Capitata' 1654 Flowering Crabapple Malus species 1653 Flowering Crabapple Malus species 1650 Flowering Crabapple Malus species 1663 5 i Red Pine Pinus resinosa Under Building 9 1644 29 i London Planetree Platanus xacerifolia Upside-Down triangle 1638 20 i Doublefile Viburnum Viburnum plicatum 1637 Doublefile Viburnum Viburnum plicatum 1636 Redvein Enkianthus Enkianthus campanulatus 1629 Sargent Viburnum Viburnum sieboldii 1628 16 l Common Witchhazel Hamamelis virginiana 1627 19 v Doublefile Viburnum Viburnum plicatum 1626 25 i Thornless Honeylocust Gleditsia triacanthos inermis 1621 28 i Flowering Crabapple Malus species 1620 28 i Flowering Crabapple Malus species 1619 Flowering Crabapple Malus species 1618 Kousa Dogwood Cornus kousa 1630 Honeylocust Gleditsia triacanthos 1634 Eastern Redbud Cercis canadensis 1635 Apple (Newton's) Malus species This apple tree is a direct descendant of the tree under which isaac newton is said to have conceived the theory of gravity. A gift of the national bureau of standards to edward o. vetter 42