TAG

# Chemistry

2026-11-08

Time-Traveler's Guide: Walls Collapse in Heavy Rain? How to Burn Modern Portland Cement from Limestone and River Clay

If you travel back to antiquity, why do mud-brick houses collapse in rainstorms while sticky-rice lime mortar takes decades to cure and dissolves underwater? Here is the complete inorganic chemistry and 1400°C shaft-kiln guide to making hydraulic Portland cement from 3 parts limestone and 1 part river clay.

2026-11-04

Time-Traveler's Guide: Tired of Dark Paper Windows? Here Is How to Fire River Sand and Plant Ash into Crystal-Clear Flat Glass and Mirrors

【Time-Traveler's Hardcore Tech Guide · #08】In pre-industrial centuries, winter meant choosing between freezing winds or sitting in pitch-black rooms behind oiled paper windows, while royalty peered into blurry bronze mirrors. Grounded in silicate glass chemistry and citing Song Yingxing's 'Tiangong Kaiwu' and 16th-century Venetian Murano recipes, this guide shows how to combine white quartz sand, soda ash, limestone, and pyrolusite (MnO2 'glassmaker's soap') at 1150°C to craft clear flat window glass and silvered mirrors.