P Pacioli, Fra Luca, 76, 77, 80, 84, 86-91, 133 Padua, 125 Painting, 4-7, 29-32, 43, 44, 71, 72, 91, 99, 105, 110, 112 Palatine hill, 135 Palazzo della Signoria, 12, 21-25, 103 Palazzo Vecchio, 12 Parachute, 71 Paris, 44 Parma, 138 Pater, Walter, 161 Pavia, 51, 58, 125 Pazzi conspiracy, 21, 23, 25 Pazzi, Francesco de’, 23 Pera, 95 “Periscope,” the, 89 Perugia, 96 Perugino, Pietro, 13, 33, 107 Pesaro, 93 Peschiera, 124 Pharisee, 118 Philiberta, 142 Phyllotaxis, 79 Physics, 17 Piazzetta, the, 87 Pincio hill, 130 Piombino, 93, 139, 154 Pisa, 25, 100-102, 110 Pitti Palace, 31 Plague, _see_ Bubonic plague Plants, study of, 79, 80 Platonic school, 54 Pliny, 23 Plutarch, 81 Pollaiuolo, 53 Ponte Vecchio, 31 Pontine marshes, 139, 154 Pope Alexander VI, 82, 92, 102 Pope Innocent VIII, 63 Pope Julius II, 124, 127, 128, 130, 131 Pope Leo X, 130-132, 139, 142-146, 153 Pope Sixtus IV, 21, 33 Porta del Popolo, 129 Porta Romana, 29 Porta Vercellina, 79, 115 Porto Cesanatico, 94 Portugal, 26 Predis, Bernardino de, 47 Predis, Giovanni Ambrogio de, 43, 44, 47, 56 Ptolemaic theory, 48 Ptolemy, 23, 54, 103 Q Queen Claude, 152 R Raphael, 107, 131, 137 Ravenna, battle of, 127 Red Book of the Painters of Florence, 19 Reflection, law of, 56 Renaissance, 89, 104, 125, 161 Riario, Girolamo, 21, 38 Rimini, 93 Rome, 9, 33, 47, 69, 128-146 Romorantin, 150, 152 Rosate, Ambrogio da, 63 Rumford, 56 Rustici, Giovanni, 118